NPCs, even bosses, aren't supposed to *have* accuracy over 100%. If these S&V bosses DO, then it is most certainly something that directly discriminates against Shadow tanks, because we have lower mitigation than our counterparts.
The devs have stated that they are capable of adding an "autohit" tag to an attack (Riposte has this tag for players), but they only use it for wipe mechanisms or things that players should *never* be able to resist (phase change control/damage effects). Most attacks against a tank *should* be able to be resisted, especially the attacks that are being mentioned here. It should also be mentioned that the bug isn't that Resilience isn't working; it's that Resilience is getting taken off *early*, right before the attack you want to avoid hits.