It doesn't even matter if you can calculate multiplayer equilibrium. It's not the solution the same way it is in heads-up. You can still lose if you employ the equilibrium in multiplayer unlike in HU.
I don't think you're correct saying it doesn't affect poker as people were able to notice and analyze this before solvers. It's true though that no-limit Holdem as played today (two blinds,no ante,deep stacks) is likely not strongly affected by the phenomena. I don't agree Pluribus experiment shows much when it comes up practical play. Not enough variety of skill levels, not enough hands and not enough time for metagame (people adjusting to how others play) to develop. I do agree pure equilibrium play is most likely not terrible in cash game nlhe but definitely not in poker in general.