ok, instead of fanning the argument out into things everyone agrees with, let's stick to the point I disagreed with:
transactions that would be accepted by old nodes may be invalid according to the new rules.
that didn't happen with segwit, it was implemented using the so-called "safe" soft fork design
you implied it could, and that was wrong
This post of yours is what I am referring to (here quoted in full). In here, you imply that the quoted statement here (not the other about "new rules" which I'd say is still not wrong, just formulated in a misleading way) is wrong, or what you "disagreed with". But if you now agree this statement is correct and you no longer disagree with it, then all is clear to me. (And if you already agreed to it earlier, I must have overlooked that in your previous post - sorry for that.)