It's somewhat dependent on the game (no one cares for Awakening Lunatic+, for example), but the people who care about this kind of thing - unit viability, investment costs, etc. - are the fans who play these games multiple times over and probably end up desiring more of a challenge than normal mode. I rarely see discussions about normal mode if it's not clarified early, and if clarification is asked for, they usually say hard mode, at least from my own experience. It's a common sentiment that the hardest difficulty is where units are pushed to their limits, and so that's where their abilities matter the most.
For this context specifically, there's enough BEXP in RD normal that I don't think most people care about it as a cost for units like Meg and Fiona. What matters is how well they use it and where it gets them.
It's possible more recent games differ. I barely discussed Three Houses online at all, and when I was discussing Engage a lot of people hadn't yet gotten to Maddening (but also Engage discussion is scarce in general).