All of that could increase discoverability of the version with only 15 minutes free trial, so it would be essentially trading sales for advertising.
That said, 2 weeks evaluation on a tool you might use only once effectively means it's just free. Those who might have a need say once a month might just uninstall and reinstall it, and feel completely justified because they didn't get their 15 days, only one day.
But it wasn't "essentially free". For myself, whenever I encounter a tool I might want to use and it has a limited time trial, I typically skip it unless I'm already fairly certain that I'll keep paying for it after the trial period. I think loss aversion comes in here as well: I'm worried about "wasting" the trial. It's like consumables in a video game: yeah maybe this tool would be useful now, but what if I encounter something later where it would be more useful?
You've just described enshittification 101.