I don't think it'll be a walkover final in either direction. The reason Emma has been smashing her opponents off the court is at least in part because they've been caught off-guard by someone supremely confident in her own game, and haven't been able to adapt. But Fernandez is clearly a different challenge because she's shown no regard at all (on the court, ie in a good way) for her opponents' reputations, and had no doubts about her own game plan.
On the other hand, Leylah Fernandez hasn't been able to dominate, "merely" stay in the match. So, I don't see her succumbing to any pressure Emma applies, nor do I see Leylah being able to win easily. Hard, then, to look past another three-setter.
Also at this point I genuinely don't care which of them wins. Leylah's matches against Kerber, Svitolina and Sabalenka have been absolutely thrilling to watch, the first especially, and Raducanu's serene progress through her draw just so in a completely different way, and so finally I'm just interested in the match. They've both done enough to make me a fan of both for the rest of their, hopefully long and successful, careers, and it almost sucks that they can't share the prize.