Fully supported and I believe he should keep him on the bench more atleast he would know that he needs to adjust his gameplay to suit the situation of the team, if am not mistaken the number of times Manchester united have fell short of supposed victory that would have gotten and then later drew or lost the is more of the fault of Onana and just countless errors in his goal post.
It happened repeatedly because the mistakes he made cost the team full points in the match and if you look at Onana who always makes mistakes, it is only right that the number two goalkeeper is given a chance to play. The coach did nothing and trusted Onana more as a goalkeeper even though we know many mistakes he made.
Luckily Manchester United did not lose in that match, but what is quite regrettable is how the second goal was scored by Lyon in the added time so that Manchester United failed to maintain the victory.