Of course EQ can help with room reflection! In a square room you'll have a resonance at a given frequency, and you can mitigate a bit this problem with an EQ. But usually EQs are used too add bass and do more harm than good.
By room reflections I mean higher frequency reflections that result in comb filtering and spatial and temporal smearing of the sound, rather than lower frequency resonances that result in the standing waves you mention. EQ can reduce the effect of room resonances, but it still can't fix the extended decay time at those frequencies[0].
[0] DRC can improve this, but only within a small sweet spot.
