Remedy alienated a lot of their fans back when they abruptly switched to Xbox exclusivity for, heh, Alan Wake's original release, with some bad PR statements that made things worse.
It was unavoidable as I think AW was in development hell and/or almost ruined them financially, but then they kept going with the Microsoft exclusivities (maybe part of the original deal?) and for a while still they seemed to barely be doing ok or again be on the verge of bankruptcy. Didn't they do that Humble Bundle for AW where they practically begged people to buy it to support them or something?
They may have gained some of their fan base back, and personally I am still a (reluctant) fan, but it's clear (from the Epic deal too) that they are not able to self-publish or stand on their own.
I guess the remaster, as it's typically the case with most remasters, is a re-release with a bare minimum amount of work, to get some extra funds for the next title. They cannot afford to put significant effort (hence resources, time and money) into it and no publisher would really support that with a sufficient budget.
They also may want the "first" one to already be available on every modern platform when they'll be releasing the second one.
Probably also an interest check for the series, although I'm not sure how reliable that is, considering most people who were interested in it would have already purchased it for filthy cheap or even got it as a freebie.