This is quite interesting.
Basic story: Doing a dry run on a planned conversion from xf1.5.24 to xf2.1.7
When we got to this addon, this happened:
We had the old version of "Ignore More" on 1.5.24 (v1.1.0c) and we simply dropped the latest version in the package for the conversion to 2.1.7, using the latest 2.0.1 release of "Ignore More". As you can see the screenshot, the new version with the logo is there but it's still reporting as a legacy addon at 1.1.0c. It does not show up in the 'Installable Addon' section, both versions just show up in the legacy area at the bottom.
I'm skipping this one for now and completing the rest of the conversion.
No other glitches in the conversion aside from this one. I was hoping to keep the ignored data intact, carrying over into the new site.
We still got some time before the actual convert, just working out the kinks ahead of time.
Note: I did create a 2nd image and was able to install the new version AFTER uninstalling the the old version from the legacy addon list. (I've not yet checked the user data as of yet.)