They are taking their models too seriously. In fifty years these scientists’ comments will be objects of fun - rather like the comments at the turn of the 19th Century by someone whose name eludes me now to the effect that nearly everything important had been discovered.
There will be no blackhole and no reverse causation or time travel to prevent the “dreaded Higgs Boson from being found - if it exists at all.
Some patent office guy said everything that could be invented already had been.
Thirty years ago, the head of a university physics department stated to me, “We know all the important physics now. All that remains is filling in some blanks.”
I was incredulous he said it, and maintained he believes it!
Similar statements have been stated by well known scientists for hundreds of years from time to time.