In this current SSPX.org announcement, the SSPX refers to Maria Teresa Gonzalez Quevedo as "Venerable."

https://sspx.org/en/news-events/calendar/ven-teresita-quevedo-girls%E2%80%99-camp-45049

Problem: That title was given to her in 1983 by JPII.

Is the SSPX incrementally moving towards an acceptance of conciliar saints?

Of course they are: One cannot be accepted by the conciliar church while rejecting its "saints" (that would be resistance, you see, and as Fr. Cottier explained upon his conquest of Campos, "What is important is that there no longer be resistance in their hearts.").

But what does it mean to be considered venerable?

"In the Catholic Church, after a deceased Catholic has been declared a Servant of God by a bishop and proposed for beatification by the Pope, such a servant of God may next be declared venerable ("heroic in virtue") during the investigation and process leading to possible canonization as a saint."
https://en.wikipedia.org/wiki/The_Venerable

But has not the SSPX of old expressed serious reservations on this new conciliar concept of "heroic virtue?"

See this 2011 article from Fr. Gleize (SSPX) explaining new and redefined concept of "heroic virtue" (scroll down to "Third Difficulty: Heroic Virtue):

http://sspx.org/en/beatification-and-canonization-vatican-ii-3

Little by little, the SSPX is moving from integral Catholicism to integral conciliarism.

Their mass is the "mass of Saint John XXIII." today.

I attend an SSPX chapel that uses the 1962 Missal and said Missal IS the Latin Mass. What makes you think otherwise?

What are the differences between the 1962 Latin Mass and the Mass before that?

Holy Week was destroyed by Bugnini under Pius XII in 1955. 
John XXIII inserted St. Joseph in to the Canon, removed the second Confiteor and some other changes I think. Someone else knows, I’m sure.

Exactly! Well said.

Speaking of canonizations, I just saw a post on SuscipeDomine where a poster was suggesting opening the cause of canonization for Archbishop Lefebrve....by Rome.  

Did they provide any links regarding the alleged Vatican initiative?

The notion of “excommunicated” saints in the conciliar church apparently does not present an obstacle.

I can easily imagine the “canonization” speech submitted to Francis by a Dutch branding company:
“He was a man of the Church...he wuved the pweesthood...”

This was presented by the SD poster.  It appears he is hoping to get Rome to do this in the future.

Didn't St Joan of Arc get  excommunicated, and then canonized before Vatican II?

Son, your time will be much better spent pestering someone more on your level.