It’s completely reasonable for a product to advertise for a newer version. How else would you know there’s a new version that you might actually decide you want to buy? And you don’t have to buy it.
No argument from me there. A notice on the splash screen, even a tool tip at start-up would work fine, but it was a full screen advertisement, several minutes after start-up, which stopped playback (!) without warning. These interruptions are what I find completely unacceptable, and I believe they stem from fundamentally misunderstanding what the user is there for, or outright disrespect.
Advertising's role is chiefly to create demand and manipulate people into buying things, not to inform.
If one is not looking for new versions, then they very likely don't need them.