I've been doing some "googling" regarding Ilex and I think the manufacturing and world wide distribution rights were purchased recently by a UK company called OakMed. Prior to that it seems that it was manufactured and/or distributed in US by a company called MedCon. My guess is there are some unsettled legal issues regarding who owns what and that is contributing or causing the unavailability in the US. The whole thing has sounded fishy from the beginning.
I do believe your Internet sleuthing is very much on point, except that this says MedCon, as part of the deal, continues on as the distributor of Ilex in the USA:
https://www.ilexhealthproducts.com/pages/our-company
It sounds like a done deal, except I could not find any date attached to this statement.
Of course there could be a dispute or claim by some other entity with respect to North American distribution rights. Maybe even litigation. If you want to do more sleuthing I would check the U.S. District Court database because that's where such a case would be.