ICTV is the world taxonomic authority for viruses and has been updating scientific names to binomial nomenclature is recent years. The "-i" instead of "1" is because numbers can't be put into scientific names on INat so me and @douch agreed on using numerals instead.

I haven't looked to deep into how they're officializing these names but I personally haven't seen any negative feedback and they're creating them in a logical way.
And yes, there's been a recent push for updating these names here on INat. This is actually the second major wave of updates and the ICTV is releasing names group by group over time.
https://www.inaturalist.org/flags/671720

Hi James. Thanks for your concern. It's good to know we have people double-checking taxonomic changes to make sure they are appropriate. Virus taxonomy is under its own code and it works in a fundamentally different way to other codes; this has a tendency to raise eyebrows among people more familiar with the taxonomy of cellular organisms. But I assure you, leytonjfreid has done the right thing. Allow me to try to address some of the points you raise:

"Not entirely sure if this is a sourced name, as I find no reference to this name in any publications or referred to anywhere else generally."

I wouldn't expect to find references to the new name since it was only ratified recently, in August 2023. Under the International Code of Virus Classification and Nomenclature (ICVCN), it is ratification by the International Committee on Taxonomy of Viruses (ICTV) that determines whether a taxon is accepted and what it should be called. Publications only function to demonstrate the evidence for recognising a certain taxon. So it's entirely possible for a new name to only exist on the ICTV website and not yet in any literature.

"Aside from the fact it's "armadillidium1", not "armadillidium-i"..."

iNaturalist doesn't accept numbers in species names. Site administrators weren't keen to allow them since viruses represent a tiny portion of iNaturalist's overall activity. We opted to use Roman numerals as a work-around.

"I'm not familiar enough to know if this process (of 'converting' compounded names to standard binomial) requires formal publication, but I assume it would as with any binominal taxonomy or status revision?"

As described above, this is standard process when it comes to viruses.

"Well, any obscure group with poor policing won't get much feedback".

If you're familiar with virus taxonomy, the ICTV is anything but obscure or poorly policed. In a way, the ICTV is virus taxonomy. And their policing can only be compared to that of a fascist regime. And in fact, there was a lot of disagreement about this change. Multiple journal articles were written both for and against this change in ICVCN policy.

"[...] I'm aware viruses have always been treated as what us casual onlookers interpret as a "whatever you want" area for a while."

I'd say it's actually the opposite. The codes for taxonomy of cellular organisms (ICZN, ICN, ICNP) give much more freedom to differences of opinion. With viruses it's all black and white. But I suppose it could seem obscure and messy to confused new-comers.

Hopefully this makes some sense. If you still have any questions/concerns I'm happy to help as best I can.

Useful links:

The International Code of Virus Classification and Nomenclature (ICVCN): https://ictv.global/about/code
ICTV taxonomy browser: https://ictv.global/taxonomy
Publication in which binomialisation was formally proposed by ICTV executives: https://link.springer.com/article/10.1007/s00705-019-04477-6