"Fr. Issac mentions the evil of Theology of Body, specifically that "it comes from hell!" "
Thanks for the update. I know a Canadian SSPX apologist would say that there was nothing sinful per se in the conference held last month. But this is not the point, it is enough for the SSPX to concede that "following its Founder's teachings" and as affirmed by this independent priest in the link provided, to refuse an avenue for this TOB expert to speak in any Catholic Church since it would endanger the faith of many and bring Catholics to a near occasion of sin. St. Thomas Aquinas is quite clear on this.
We are even bound to resist the Roman Pontiff if such was the case.