It looks like Fibers currently supports Node 14 which will be supported until 2023-04-30, around 2 years and 9 months from now (assuming no minor patch will break Fibers).
NodeJS v15 (2020-10-21) might give us a hint on how Fiber might behave in v16 which if it turns out to be compatible with Fibers might extend the usage by another 2.5 years. Perhaps it might also help if the Meteor core team can get in touch with library author to see if he can elaborate on his statement and check if he has any visibility on near-term potential challenges. Lots of credits and respect to the author for building and maintaining this library thus far.
After thinking more about it, and reading the author’s statement, I came to agree with rjdavid, zodern, macrozon and dr.dimitru I think it is worth considering the longer-term phasing out of the dependency on Fibers to ensure Meteor can stay up to date with the latest Node for the foreseeable future.
And as jkuester suggested that refactor might indeed be on a Meteor 2.0 branch, it might also be an opportunity to modernize the entire code base to ES6, move some stuff to NPM and add types where needed, this work can be done gradually and gracefully if planned long-term correctly, it is important by not urgent task. Furthermore, by starting this effort on the right direction (i.e Meteor 2.0 branch), the meteor team/community will surely give a very strong social signal on their intention to keep Meteor around for a very very long time. And I hope benjamn has to some interest in this task, as I’m sure he gave this effort a lot of thought, at least he can be consulted on it.
Every challenge brings new opportunities for growth and I think there is enough smart/skilled people around this system with strong incentives to pull this refactor off elegantly.