Europeans are indeed prohibited from using Threads, according to Meta

Instagram released Threads in October 2019 as a stand-alone app for chatting with Instagram Close Friends. That app is no longer available as Twitter competitor Meta this week released a new Threads app. More than 100 nations, including the US and the UK, offer it, but not Europe. Meta has acknowledged that it is preventing users in European nations from accessing Threads via VPN. As a result, profiles and material do not load, and notifications do not function.

"Threads is now unavailable in the majority of European nations, and we have taken more precautions to block access to threads by residents of those nations. We expect to be able to introduce Threads to more nations in the future. Europe continues to be a very significant market for Meta", said Meta.

Within a week of its release, Threads had amassed 100 million plus users. The addition of European nations would only boost that total. Besides, likely, you won't be able to download it anytime soon in the Old Continent due to the impending Digital Markets Act (DMA).