Pretty weak argumentsLooking at Microsoft's appeal arguments,
1. They argue that the cloud isn't a separate market, which imo is a hard sell because even the EU thinks it is.
2. They argue that the CMA didn't take the 10 year deals that MS made into account. I'm pretty sure they did and just didn't think they were good enough. They also argue that the cma miscalculated MS marketshare in the cloud market. Even if that were true, I would argue that it's not enough to change the ruling given the other advantages they have in the market.
3. MS argues that it's wrong to assume ABK would have put it's games on cloud services without the merger. Wasn't there some internal documents that the cma found that says that ABK were planning to do that? Someone let me know.
4. MS argues that they would have no incentive to make ABK games exclusive to their cloud service and that even if they did, it wouldn't have an effect on the market. You could look at the massive popularity and revenue driven by COD yearly to show that isn't true.
5. MS argues that the CMA didn't consider their remedies and that blocking the deal was too harsh a response. CMA mentioned the remedies several times and found them lacking. Is it unlawful to not like the proposed remedies? I wouldn't guess so. CMA also suggested divestiture, but MS dismissed that suggestion.
The CAT does give those interested in the proceedings an opportunity to give input, so I imagine an army of shills and companies with financial incentive to push this deal will be shouting at the CAT about how they should overturn the cma soon.
Number 1 is a particularly poor argument. Every cloud market that has come into existence is distinct from what came before it. Netflix vs DVDs, Spotify vs CDs, cloud storage vs hard-drives etc