Specifically -disabledeprecation (or lack thereof) isn’t that serious, in that it would be simple for an entity like the Foundation to fork the repo (assuming a doomsday like scenario where noone has commit access) and either re-enable that feature or remove it entirely and simply release it as the Zcash Co currently does. So I think the likelihood of the network shutting down due to that flag is overblown.
As to the theme of the thread I am strongly in favour of creating a dev fund as a % of the block reward to fund continued development of the protocol post 2020.