If that is all, that would be a great solution to the problem at hand indeed. Does it require other adaptations? I guess one would need to guarantee that the migrate calls are actually included. How did you do that? I guess every package depending on libjs-jquery-mobile would need to load the libjs-jquery-migrate calls? Do you know if this can be done inside libjs-jquery-mobile itself?
Here's the documentation for using jQuery Migrate: https://github.com/jquery/jquery-migrate/tree/1.x-stable#readme
I'm not associated with jQuery Mobile other than through OpenLP's usage of it, so I don't know what their plan is going forward. I do know, however, that OpenLP is moving away from jQuery (I'm one of the developers), so it won't be a problem for too much longer in the openlp package.