First and foremost, the time for objecting to an acquisition should be before it closes, not after.
Second, forcing a company to "unbundle" like this is really an antritrust action and the bar for that should be pretty high. Objections to acquisitions can be done on potential issues. De-merging a company should pretty much be based on actual not potential violations (IMHO).
Third, all of this is over Giphy. There are alternatives (eg Tenor). This is not a market any company (other than maybe Apple and Google by virtue of owning the platform) can dominate. There's no network effect like there is with WhatsApp or Instagram. This was not a large company. Giphy was miniscule.
Fourth, creating a GIF keyboard and support in your apps is pretty easy. I imagine this is what Meta is going to do instead. So what's been achieved exactly?
Lastl, government power and attention is limited. Please let's use it for something useful. This doesn't affect anyone. This doesn't help anyone. Let's do things that do.