Massive blowback from who? People who wouldn't buy an Xbox if their life depended on it?
FFS.
From existing fans of these established previously multi-platform franchises, who rightfully would feel slighted that they are now being strongarmed into another platform ecosystem to get the latest instalment. Not to mention may already have made their choice of platform of preference and might not feel like spending a load of cash on buying a new system for a single game.
Its not good business, because you will never ever get a 100% user conversion rate, lessening the value of the franchise, and devaluing the purchase.
With something like Starfield - a new IP- this isn't a consideration, and so its a much more likely approach.
Nothing is impossible, obviously, but I'm just taking a pragmatic view. A business-minded view without personal, emotional attachment to the outcome.
Understand why practices like timed-exclusivity are commonplace:
That route gets the marketing focus on the "exclusive" property, and thus the bulk of sales and mindshare uplift to the target platform - without mitigating that value by having to underwrite all monies and brand-value lost by limiting the addressable market.
With GamePass day#1 exclusivity this becomes an even more persuasive strategy because ultimately GamePass engagement and unit sales are entirely different revenue streams. If they get someone to sign up to GP for a year to play the next Elder Scrolls, the job is done. Because ideally they'll want to sell it, and earn from it long after its driver potential for the service has faded to insignificance. By offering it then to the market beyond, they get to increase their return on investment whilst further embedding the value proposition of GamePass as a service.