This immensely.
I currently don't think when I L-cancel. It's a muscle memory. Whether or not it stays existent is not what matters to me. What matters to me is when I get slammed in the face by, say, Bowser f-smash, that it's my fault for not spacing. In fact, most problems that I can think of players having in the first place aren't even technical barriers, they're fundamentals-based.
The fact that auto L-cancel can make the technical barriers not as much the focus, but still maintain the faster pace of the game, is a well-thought-out idea to me. It's what Rivals of Aether, a game that Smashboards has backed, is doing to a degree, and it's interesting to think about what would happen if PM did the same by allowing this switch on for tournaments.