Hi Mattpryke68, not sure if you are a newbie or not but if so welcome along
I have a mail from MB UK categorically stating that a replacement roof is categorised under the parts warranty scheme of two years from date of installation, irrespective of when your vehicle warranty expires (unless of course your overall vehicle warranty is longer, but that is unlikely)
It is also worth noting that my vehicle is out of official vehicle warranty status, has not yet had a replacement roof and yet MB UK have still covered the roof issue as it is part of an affected batch of VIN numbers.
My personal view is that the new roofs (those fitted after Sep '20 and maybe earlier) may have cured the issue, there seems to be a degree of confidence about this and I feel confident that MB have your back if it does go wrong. Enjoy your MP, all will be well