I think it's very simple: if you'd describe its usage as a "skill", it's probably fine. Obvious "navigating this cheat menu UI takes some practice" cases aside.

If a professional team uses data analysis and then teaches their players something like "at 30s, on this map, this player rotates from here to here in 70% of games", that's just good training. If they have this data being live-streamed to their second monitor, it's cheating.

Those kinds of maps are already available for study outside of the game for DotA2, eg. here’s the analysis for a game I played. These are incredibly useful for learning and analysis after the match.

https://www.opendota.com/matches/5501229759/laning

I don't see as very different from a wallhack if it's any good if it's an in game overlay. I suppose if it's an offline thing that you can study but need to apply yourself that's no more of a cheat than any other prep.

I would say that a skilled player doesn't need to see the heat maps in real time, it would be enough to see them once or twice and they will remember because it "makes sense" to them that the heat maps are the way they are.