I'm with Allen. It's fine to drop leap-seconds; but then it's not UTC any more, it's a new time scale, and it needs a new name.
We've made this mistake before: in fact GMT has been redefined many times, and as a result the time interval between two GMT timestamps depends on which versions of GMT the two timestamps use, and so on the dates of the timestamps.
Allen has an instructive page on time scales here: https://www.ucolick.org/~sla/leapsecs/timescales.html
It's not a quote, but the article also has Allen saying that "it could cost between US$10,000 and US$100,000 for each telescope to correct the problem, and that corrections will be tricky to implement."
It also has another astronomer claiming problems: "But separating time from rotation would mean that telescopes would no longer function properly, according to Patrick Wallace, an astronomer at the Rutherford Appleton Laboratory in Oxford, UK. Most telescopes with a viewfinder wouldn't be immediately affected, but instruments that track satellites and other moving objects could feel the effects within a few years, Wallace warns."
It sounds like FB/Meta is correct in saying that Astronomers did object. I'd suggest (like Mata does) those objections are not especially important considering the trade-offs though.
> If the change is implemented, “the old meaning of time will become ambiguous,” warns Steve Allen, an astronomer at the Lick Observatory in Santa Cruz, California.
This does seem like a problem that is solvable.
In 2015 the ITU (mentioned in that 2003 story as studying the problem) announced:
> The ITU World Radiocommunication Conference (WRC-15), currently in session in Geneva from 2 to 27 November, has decided that further studies are required on the impact and application of a future reference time-scale, including the modification of coordinated universal time (UTC) and suppressing the so-called “leap second”
https://www.itu.int/net/pressoffice/press_releases/2015/53.a...
In 2012 they also decided to defer:
> ITU Press Release of 19 January 2012 - ‘ITU Radiocommunication Assembly defers decision to eliminate the leap second’
https://www.itu.int/en/ITU-R/Documents/ITU-R-FAQ-UTC.pdf