Since monthes I don´t get updates like it is for other programs like the XARA´s. Is magix planning further updates here (I use the V 21.01.205) or is this program an discontinued Model ?
Updates are rare and normally only deal with serious bug problems. I would think at this stage Magix will be firmly in the development stage of their next VPX release. The German site gets more Magix staff response than here. Maybe you should post this query there as I see you have posted one comment on that forum.
I think you have the current version. I am still on VPX 14.
As @CubeAce (Ray) says, it is almost certain that Magix developers are working on VPX 16, I think, so further updates to VPX 15 are unlikely, unless a very serious bug emerges. Your build of VPX 15 is the current latest.