Unlikely. I've been a regular user since 2006 and both on the web and the apps, the algo timeline has been there for a long time but I never use it.

I mean it's there, as in, there's a button to switch to it, but I don't think I've ever had it switch automatically.

The one thing that is mighty annoying though, is how it keeps pushing "recommendations" on you. The "someone liked", "someone follows someone", this kind of stuff. If only there was a dedicated button to make someone else's tweet appear in your followers' timelines... I somehow managed to break that misfeature by muting a bunch of "words" that are apparently contained somewhere in the recommendation objects because apparently the mute feature checks not only against the text of the tweet but against some kind of serialized form of it. So I no longer have these neither on the web nor in the Android app.

In my experience, those "recommendations" only appear in the algorithmic feed. Are you sure you haven't been using it unknowingly?