On the merits and after the agreements with Ubisoft and Sony, the case is pretty much in favor of MS. But if the 9th Circuit agrees with the FTC on the issues related to the PI (preliminary injunction), it could force MS to settle with the FTC (to avoid at least an extra year of litigation and slowing down the integration with ABK). Therefore, maybe they have to make some extra concessions to the FTC (likely behavioural).
It's unlikely but not impossible.
In fact, it's not farfetched to think that Blade being announced without platforms is a legal precaution. After all, the exclusivity around the games from Zenimax has been a hot topic since December 2022 (when the FTC decided to block the acquisition). Days later the European Commission released a statement contradicting some of the arguments from the FTC regarding Zenimax and exclusive games, months later Sony highlighted to the CMA that the PS5 version of Redfall had been cancelled, and in June 2023 during the PI process it was brought up multiple times (the renegotiation of the contract with Disney to make the Indiana Jones game exclusive, all the internal meetings about Zenimax games being exclusive or not, Pete Hines not happy because COD was still going to be multiplatform but Starfield and Redfall had to be exclusive or even Phil Spencer backtracking a little on the idea of Elder Scrolls 6 being exclusive).
We know that the ABK case has affected MS/Xbox from a business point of view because cloud gaming was all the rage in 2021/early 2022 but as soon as concerns in relation to the cloud gaming market started to arise, MS started to downplay it more and more: they reduced investment close to zero, Matt Booty called it "experimental" in June 2023, no more talk about streaming games already owned (until weeks ago in Brazil), no more cloud games with specific mobile UI since late 2022, no more games added as F2P to xCloud like Fortnite (the original PR said that more games were coming soon), etc.
So, maybe it's a marketing gimmick but it could also be a legal issue that they know that has to be kept under control in the present (with the FTC appeal) but also even thinking about the future (more big acquisitions are likely coming if they want to be number 1 in revenue by 2030).
It will be interesting to see what happens with the next game announced by Zenimax during 2024 (specially if the FTC case is still alive).