Precisely the reason why "voting with your wallet" is meaningless in this scenario. If sales on Steam are high, they take it to mean there were no consequences for the year-long exclusivity period. If sales are low, they take it to mean that demand is higher on EGS so they made the right choice by going exclusive. There is no way for consumers to properly voice their displeasure with the practice, and that's why Epic throwing around ill-gotten Fortnite money is a cancer on PC gaming.
The highlighted part strikes me as unlikely. Steam is still the largest virtual store, and it's still a true-ism that video games make the far majority of sales in their first two weeks. Remedy certainly isn't expecting anything near those sales now that it comes on another platform.
What remedy is going to do is pretty predictable: they're going to check how well it sells on steam, and after a few more weeks they'll check their total profits (so the (larger) profits/game of their EGS sales, whatever money they got for the exclusivity and the profits/game on the steam store). Then they'll compare it to their projected sale amounts and projected profits. If their sale amount projection is lower than their actual sales (so EGS plus steam combined) by a considerable margin, then they (hopefully) conclude that the group of disgruntled steam owners(1) is large enough to rethink their strategy.
However, the other factor (profit) is important as well. More important for their business (developers gotta eat), but IMHO not by much margin. The exclusivity deal and the higher profit per game (as well as whatever steam sales might rake in) might certainly push the profit in green numbers. If it actually IS above expectations, it's likely they keep on EGS.
The interesting part, of course, is if these two factors aren't in allignment. If their profits are higher but they sold their games to fewer people(2). If these numbers aren't far apart, I think they'll probably keep doing it. But they certainly know that customers often do the PR for them. If control gets review-bombed(3) (and as strange as I find that habit, I can predict that happening now), it might damage the long term goals of the company.
TL;DR: I think the only thing you can really do is massively and collectively NOT buy the game when it hits steam...and hope that remedy hasn't yet sold enough copies of the game to make it worth their while regardless.
(1): I'm in two minds on this. I honestly don't mind steam having a bit of serious competition, but I rely on proton a fair bit for my gaming habits, so as such I've got to cheer for valve
(2): the reverse - remedy makes more sales but has lower profits - is rather unlikely with their profit margin being better on EGS
(3): yeah...for some reason people intentionally BUY games to leave bad steam reviews on them. I...don't get why, but they do.
