See their letter here.
1. "We reaffirm our adherence to the Magisterium (including the Magisterium of Vatican II and its successors).
What then of the clear Errors of Vatican II and the Novus Ordo?
2. "We are ready, like every Christian, to ask forgiveness if some excess of language or distrust of authority has crept in among some of our members. We are ready to convert if partisanship or pride has polluted our hearts."
Ask for forgiveness to the Traditional faithful for a deficit of language on the Errors of the Crisis.
3. "We would like to meet a person who is for us the face of the Church's motherhood."
Ambiguous statement.
4. "They were promised that "all measures would be taken to guarantee the identity of their Institutes in the full communion of the Catholic Church"
The SSPX was and is in full communion, as will you be if you refuse to accept the Errors and insist on the rights of Tradition (not just a personal charism). Where is Catholic Truth being proclaimed in this letter, with the courage of risking being illegally suppressed by the Vatican?
5. "Pope Francis "invites pastors to listen with affection and serenity, with a sincere desire to enter into the heart of people's drama and to understand their point of view, in order to help them live better and recognise their place in the Church" (Amoris Laetitia, 312)."
Quoting a heretical document.
6. "We are eager to make our modest contribution to this harmonious and diverse unity"
The Novus Ordo Missae, a Protestant presentation of the Mass, is not part of "diverse unity," nor is the TLM in unity with it.
7. ""We must avoid judgments that do not take into account the complexity of the different situations.... We must help each person to find his or her own way of participating in the ecclesial community, so that he or she may feel that he or she is the object of a mercy that is 'unmerited, unconditional and gratuitous'" (Amoris Laetitia, n° 296-297)."
Quoting again a heretical document.
Conclusion: this reads like Trad Stockholm Syndrome, rather than any Profession of Faith. Act guilty, plead for forgiveness, so your captor/kidnapper won't end your life. Instead of standing up for Christ and His Truth on the matter (liturgical orthodoxy). It is a disheartening letter to read, to be frank.