These are group endgame content from Legion, for 20+ people. There is no reason to expect that a level 38 in the new squishiness would be able to solo them. I don’t even know how a level 38 would compare to a Legion level 110 in power.
See also
From that report, it seems that a current level 50 with some gear has no problem, and I would hope that would also apply to a level 60 when Shadowlands releases.