mtp as in media transfer protocol? i fail to see what this has to do with the display server. and what do you mean with web transparency? never heard that term and google does not give any infos. If you mean something like network transparency, wayland can do that with e.g. waypipe (https://gitlab.freedesktop.org/mstoeckl/waypipe). but not tested myself tbh.
mtp has nothing to do with the display server. X11 has no mtp function either. its completely independent from that.
and i can only talk about KDE, but it has a own solution integrated which then mounts android folder in its file explorer (dolphin) while unfortunately blocking mtp over CLI at the same time. you get an “likely in use by GVFS or KDE MTP device handling already” error then.
It is possible of course that this is a thing that happens only under KDE wayland, but not because it is wayland itself but because the wayland version of KDE is maybe newer or was configured differntly by the devs.
that said, if it does not work as expected, report it as bug. usually things are fixed very quickly.
