@domubpkm If you understood the workload involved to update Qt and it's submodules for an old version you would probably also understand that this is more than one should ask for in the first place.
The short answer is no, the long answer is: there is no sane point in keeping unsupported things around if nobody cares for (not "cares about") them. In other words: Suppose I care about pudding, I don't care for it, hence I want to consume pudding, not watch it grow mold.
In the end people need to move on, and as long as people stick with xenial just because they believe there is a point (that includes port maintainers, system integrators, app developers, and users) the resources will be spread too thin and the result for focal and what's beyond will look poor. The only real solution is to move on fast, period.