That's not what it says exactly, though.
These are out-of-context anecdotes written by the poster on the wiki, not quotes from the writer.
Nowhere does it explicitly say that they used the designation of the IDW comics to distance from Bumblebee. That's inferred from a second-hand account. That interpretation is something you might think based on what someone said about what someone else said.
What we see in the comic, more importantly, is:
1. All realities are the same designation as the continuities that they branch from.
2. The Bayverse should, as a result, be a branched timeline from the original continuity.
3. It branches, very specifically, from the events of the Bumblebee movie. This isn't really arguable, it's what the comic literally shows us.
4. The designations are based on medium rather than universe, so really, the "Gamma" part doesn't make it a separate universe to Bumblebee.
I personally just find the reading that it is the same universe as Bumblebee and they're branching off from it more consistent with the story. Even if not, it still implies that the exact same events from Bumblebee were happening no matter what reading you ascribe to it.