To me it is how it sounds. Anything past that emcompasses style and technique. Which could collectively be considered tone I suppose.
I would agree that technique can have some impact on tone. For example, a beginning violin player will have pretty horrid tone! The same can be said of a beginning flautist (flute player), saxophonist, clarinet player, and some other instruments. Recently, I tried playing flute after having not played for quite some time. My lip is pretty flabby and my tone was pretty bad - quite breathy and pitchy. So, I need to put in some work to get both my tone and technique back! So, I acknowledge that there is a sense in which technique can affect tonality, but that is limited.
The problem is that guitar players (to include some very well-known players) conflate the terms. The word “tone” is expanded to mean more than it does, and the word “technique” is constricted to mean less than it does. Unfortunately, we have a bad habit of limiting the term “technique” just to concepts of speed and precision. It goes beyond that. I think “style” is a great synonym. All of those subtle nuances - pick attack, vibrato, string pressure, dynamics, phrasing, timing - these are elements of a person’s personal technique, “style”, if you will. That is why a player (BB King being the current example) can play on different rigs which do sound different, yet still sounds ”like himself.” This is what makes him so memorable. In a way, it reveals that people don’t care about the tone of your rig nearly so much as they care about how you play your rig!
Now, I don’t really fault players like Bonamassa and some others for making statements, like “tone is in the hands,” even though it is objectIvely not exactly correct. Too many players chase tone in endless gear acquisitions, hoping to become better players. A statement like, “tone is in the hands” is a good reality check to someone that no amount of gear is gonna make you sound good if you don’t put in the work. By “sound good” I mean the totality of a person‘s playing.
Nevertheless, I don’t think that is reason to keep misapplying terms.