To be fair, in the recording I linked above, they said at some point the Zoom limit of 100 people was reached and they said they still had people trying to join. Also there were a few younger comrades in the Q@A.
Unfortunately that's par for the course in Marxist academia. Academic careers take forever and Marxist academia wasn't really able to reproduce itself since the 90s. The very young aren't at that level yet, so the pool is just terribly small. Also most younger Marxists have a tendency to somewhat scoff at more academic and scientific education from my experience.
Also, as with all older comrades I've met, they're horrible at playing the new medias due to their age and own experiences. They desperately need younger comrades to get their shit up to the 21st century in terms of marketing, etc.
Can't be overstated how important this is. Combined with the new solar parks going online this year and over the next couple years, this should really alleviate one of Cuba's most essential struggles. Electrification and sufficient power generation plus an ability to maintain this stuff with spare parts (unlike the old Soviet and GDR stuff they still run) are the lifeline for the Cuban revolution.