The RHNA rules are riddled with loopholes, and cities are already finding creative ways to jumping through them. Most notably it does not strictly require that zoned capacity be likely (or even possible) to develop.

You'll find examples where cities have proposed rezoning mountain-side lots on steep ravines in order to fulfill state RHNA mandates, knowing full-well that any actual project would be unbuildable. Time will tell if state regulators will have the teeth to go after cities for this kind of blatant bad faith NIMBYism.