I think Cover and EN management have a fundamental misunderstanding of their overseas audience. And this isn't just about Tempus, mind you. Their assumption from the very beginning was that they needed to tone down the Japanese/otaku-y aspects of Hololive to make HoloEN palatable. So Myth and especially Council/Tempus got serious lore instead of "cute dog who works in a bakery". EN management was hostile to the idea of numbered gens and even to the idea of ENs calling each other senpai and kouhai (they eventually dropped their opposition to this). It's a weird mistake to make given that Hololive got popular in the West because of translated clips of talents like Fubuki, Korone, and Miko.

With Tempus it's not about the fact that they exist (there is a HoloJP after all) or that they collab with the girls (again, something that occasionally happens on the JP side), but with the subtle pushes to try and get fans to see them as part of HoloEN--the pushing of the Holopro EN label, the Tempus logo insinuating that they're EN3, etc. It's kind of tone-deaf, as if they don't realize that most of their fans are only interested in the girls even if they're not necessarily unicorns.