I’d like to hope this isn’t intended and is a bug, as it removes a lot of counterplay on the part of thieves. Using steal, and other shadowstep abilities both into and out of the traps can proc the Test of Faith threshold damage, and can also proc the Dragon’s Maw control effect.
I haven’t tested it with mesmers blink or other similar abilities unfortunately so do not know if this is an intended consequence of shadowstep itself.