This is a case where mergers are expected to make prices go down. As opposed for substitute goods, like macbooks and dell laptops, where a merger would probably make prices go up.

In both cases you have a prisoner's dilemma between vendors - with vendors producing substitute goods, the "defect" option is to lower your price. (This makes you more money, but costs the other vendor more money than you made.) For substitute goods, the "defect" option is to raise your price (this makes you more money, but costs the other vendor more money than you made.)

So mergers of vendors of substitute goods are usually bad, and tend to be blocked, because once merged the companies can coordinate to raise prices. But of complement goods are usually good, and tend to not be blocked, because once merged the companies can coordinate to lower prices.

All this to say that I think this move makes sense for apple regardless of whether their relationship with Adobe has soured.