I haven’t experienced it myself because I have stuck a post-it on my screen on the icon of Netflix and Mx player pro which say “DO NOT UPDATE” 
.
To be serious, @Philips_Support_P explained previously that when you uninstall a pre-installed app, it’s icon comes back on the main screen by an internal routine.
@Philips_Support_P, more detailed information upon this ?
Edit : seen on another thread about Netflix, but should be the same for MX player pro :