I wish they'd bring RE3 Mercs back.
i think re3 mercs type maps could be incorporated into raid mode tbh- the framework is definitely there for how it's laid out- there just needs to be actual map design (similar to rev1's ghost ship) with added hostages and a timer (that works off mercs mechanics)
the big issue is that it'd be hard to get the kind of 'balance' that re3 mercs had in terms of difficulty as whole point of the mode was condensing that efficiency between resource usage (to kill monsters/rescue hostages) and movement between areas that embodied the core old RE gameplay
with more action-based gameplay it'd be really rough to get that right, especially with custom loadouts and co-op- it'd be similar in terms of execution but radically different in spirit