My first post in this thread which i just browsed through...
I know what you're saying above, you're fine in that regard. As TB suggests, take a look at a person's profile info when reading their posts just for a point of reference in where they are coming from. You are obviously a much in demand player, especially in your genre, and that doesn't come from being "wrong" so take lightly comments from guys who don't appear to have Latin music cred...including me! But I am fair-minded and listen with an open, unbiased, non-jealous ear.
If you didn't have a bunch of bass players (players of unknown capabilities and unknown genre awareness) WATCHING your playing, complete with boosted bass, your "overuse" of glissandos would not have been noticed and pointed out. Your playing is excellent. You are obviously a skilled and tasteful player, especially showing in the "non-uncle" vids where you get to let loose. In those songs you play way more notes and it's certainly not overplaying. So, your uncle is seeking a sound different from those other bands, and that's fine. You know him and the latin genres better than most of us so go with your gut. If he wants less chromaticism then give it to him; hopefully, he'd be cool with more groove playing though- I understand and use empty space but, damn, you were leaving huge gaps that, to me, there's no way it can be said you are playing too much. Too much chromatic for him, okay fine but overplaying- no way. But he's the bass. Hopefully just dropping the chromaticism will make him happy. Again, WATCHING your relatively advanced playing techniques with boosted bass is obviously a factor in some of the guys' posts here who say you are doing too much. Great playing, there's a reason you are in high demand, including from one of the biggest guys in the genre....