Last year, the SSPX parish in my city did not genuflect at the Good Friday Prayer for the Jєωs, but this year (today) it did. Has the SSPX changed which Missal it uses for Good Friday and Holy Week in general?

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Good question, and intelligent observation. 
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I did not attend an SSPX chapel today, but it was traditional Latin, private chapel. The priest inserted the genuflection and "levate" after the perfidious Jєωs prayer and everyone in the chapel genuflected except me. Last year two others did not, one of whom couldn't bend his knees and the other one told me he remained standing knowing what prayer it was. The first man with the bad knees passed away recently, and the other man said he just forgot to pay attention.
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My missal said to genuflect.  Is there an older missal which says not to?  And why?

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My Fr. Lasance missal is from 1945. It does not have genuflection after that Prayer for the Jєωs, but it does not explain the reason for the omission. 
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Any real traditional priest can explain to you that for the first 1900 plus years the Church did not genuflect after that prayer because of the mock genuflections and derision these Jєωs committed during Our Lord's ILLEGAL trial (night time trials were forbidden by Jєωιѕн law, which is why they hastily convened a quick mock trial at sunrise to officially confirm the judgment they had already made TWICE during the night -- first, at the residence of Annas, the surviving and older High Priest, and second, at the residence of Caiphas, the High Priest who had taken the place of Annas not unlike Francis taking the place of Benedict XVI for the first time in Church history). 
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Even in his abysmal betrayal and blasphemy against God, Caiphas exercised a kind of papal infallibility when he prophesied that it is expedient for one man to die for the people. 
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Therefore, the Church does not genuflect for the Jєωs because the Jєωs taunted Him, struck Him and spat in Our Lord's face before handing him over to the secular authority for execution. We do not imitate their gesture nor do we honor them for they have dishonored themselves and their children.  They did so willingly, saying, "Let His blood be upon us and upon our children."
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When we go to Mass and to Good Friday community prayers, we should be aware of what we are doing, and not simply following the crowd without knowledge.
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My missal said to genuflect.  Is there an older missal which says not to?  And why?

My St. Andrew Missal (1947) expressly indicates NOT to genuflect when it says right after the introductory prayer:

"Here Oremus, etc. is NOT SAID, but the celebrant proceeds as follows: "Almighty and Eternal God, who drivest not away from Thy mercy even the faithless Jєωs...".

The "etc." part refers to "Flectamus genua. Levate" (Let us KNEEL, arise)


It was Pope Pius XII who first instituted kneeling for this petition as part of his revision of the Holy Week liturgy in 1955, so it makes sense that the 1962 Missal the SSPX uses, contains the modifications:  

"Let us pray also for the faithless Jєωs: that almighty God may remove the veil from their hearts; so that they too may acknowledge Jesus Christ our Lord. Let us pray. Let us kneel. [pause for silent prayer] Arise. Almighty and eternal God, who dost not exclude from thy mercy even Jєωιѕн faithlessness: hear our prayers, which we offer for the blindness of that people; that acknowledging the light of thy Truth, which is Christ, they may be delivered from their darkness. Through the same our Lord Jesus Christ, who liveth and reigneth with thee in the unity of the Holy Spirit, God, for ever and ever. Amen.^"

There was an awkward and noticeable (to me, anyway) pause as our priest failed to say the "perfidious" part of the prayer. He appeared to read it in the Missal, but then remembered not to say it. It was, as I said, awkward.

Nearly everyone genuflected, except a couple folks. The genuflection "command" was given so most did so.

For what it's worth, last year the "perfidious" part was said. Different priest, so I am not sure what to make of its excision this year. 

Oak Park, Illinois (right outside of Chicago) at Our Lady Immaculate:

There was a genuflection for the conversion of the Jєωs, fortunately.

Wow, that was a typo on the fortunately. Mea culpa...

Fr. Trincado

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The audio is really bad in this video and I can't understand what's being said, if anything.
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