If life lacks any meaning and we react in the way Camus wants us to then we can focus on other things and personal human projects. Does this mean that immortality becomes desirable?
If life is absurd, immortality might be a continuation of the absurdity - and worse, because life ends but immorality goes on for ever. An eternity of absurdity! What a prospect.
However, if immortality provides an extension of our ability to 'focus on other things and personal human projects', then it looks attractive - unless the other things and projects drain themselves of interest eventually and nothing new and absorbing can take their place.
From a purely logical perspective, the question is not answerable.
The desirability of immortality does not stand in any necessary connection with whether life is absurd or meaningful.
Syllogistically, you are asking if A=B, does C=D follow?
So what is necessary is to add some premises which link meaning or lack of it to desirability or undesirability of that state of affairs.
Here's some further things to consider:
Would living a meaningful life, though in perpetual agony, make immortality attractive?
Is there anything about absurdity that makes it desirable or undesirable, or do other factors come into it?
We all know that 'Man is mortal'. We need not desire for mortality. So the thing we can desire is to become immortal. There may be personal difference in the idea of immortality. We can't deny this even if the truth is something else. It may be an immortality that transcends this absurd life. But only those who believe that there is something immortal would desire for it.