mamba
Legend
not sure it is, that depends entirely on what you actually cover and how important it is that every single video is about the same TTRPG.Only if they all go to the same alternative content.
If I have 10,000 subscribers right now on my 5E channel and they all leave -
1. If ALL of them go to PF2 I could follow and continue with little impact to my business (aside from the time to learn a new system)
2. On the other hand if 2000 go to PF2, 2000 stay on 5E, 2000 go to COC, 2000 go to SotWW and 2000 go to GURPS. Now my business model is destroyed.
And as I said before, I do not see 5e getting drastically smaller right away anyway, so I am not concerned about your scenario. I do however hope that it does get smaller and that youtubers branch out to cover other games and help with this.