[kevinslashslash]

Gingerbread, Android 2.3, was released December 2010 for phones.

Honeycomb, Android 3.0, was released Feb 2011 for tablets. It was a radical new UI and introduced several new APIs. It was the largest Android update ever, except that no devices were updated to it. Android tablets didn't sell very well and developers had little to no reason to support Honeycomb.

Ice Cream Sandwich, Android 4.0, October 2011. This refined the Honeycomb changes and was appropriate for use on phones. It did work on tablets but wasn't really optimized for them until 4.1/jellybean.

Honeycomb wasn't a fork or anything, but the strong divergence and poor sales of Android tablets meant that no one wanted to target Honeycomb until they were actually targeting Ice Cream Sandwich, and then at that point it was barely worth supporting Honeycomb tablets, but still work supporting Gingerbread phones.

I don't think it's particular relevant to the iPadOS situation.

[vmlinuz]

Technically, there was at least one device updated to Honeycomb - the HTC Flyer was originally released with Gingerbread and was later upgraded. I know, because I've still got mine, as handed out by Google at workshops where they tried to persuade everyone to use Fragments for everything. I think they've largely stopped trying by now...

Also relevant, that Honeycomb wasn't released into AOSP until ICS, which meant there were no third-party builds or even support from off-name brands.