It is perfectly legitimate.
We're not talking about digging up personal faults of a priest, their past lives, etc.
We're talking about a Priest (a public person)'s public or semi-public (as opposed to private, given in confidence) words about a very important topic -- the change in direction of the SSPX.
Catholics are caught in the middle. They have to be able to plan where they will hear Mass next year and the year after. They have to know if they need to move! They have to know if their Mass and sacraments are relatively safe (nothing is ever guaranteed, I realize). Especially in terms of doctrine!
So yes, anything a priest has said at Mass, after Mass, to a group of Faithful, to a group of children, etc. is fair game to be reported here on CathInfo, and should be taken as a good faith report by the readership.
Catholics aren't inclined, nor do they go out of their way to lie. I don't believe the whole "spontaneous increase of satan's power over SSPX Catholics" theory, no more than I believe the Big Bang theory of creation! Both don't make sense.
Those who hate the Resistance would have you believe that one fine day, hundreds of faithful Trad Catholics all around the globe suddenly decided to give up on and torpedo their spiritual lives and start being evil, discontent, rumor spreaders, slanderers, etc. But as for having a point, or something concrete to resist? Oh, no! It's all in their demented, devil-owned imaginations.
Sorry, I don't buy it.
Likewise, they say that the aforementioned "evil elements" are new to the chapels and/or sedevacantist anyhow, and were never friends of the SSPX.
They only wish.
On the contrary, I know plenty of resistant SSPX Catholics who supported the SSPX for years if not decades, some of them with a large level of support (time and money). I know ex-seminarians in this category, who were willing to donate their very selves to the SSPX and its cause. So much for that bloody lie.
And I happen to know for a fact that at one large chapel of the SSPX, large numbers of parishioners left -- but less than half of them went to the local Resistance chapel. The rest are warming the pews at their local Sedevacantist chapel! That tells me there are real problems in the SSPX.
So yes, in this struggle we NEED to keep each other informed that YES, there are concrete, real problems in the SSPX. It serves to "confirm our brethren in the Faith", as it helps those resisting to recall (once again) that yes, you are doing the right thing.
It depends on one's personality type -- some personalities need this confirmation more than others. But if it helps us to persevere, be steadfast (as opposed to lose heart and compromise), then it's a good thing.