Actually, having done a bit of digging I'm not too sure about this. Apparently converting the files will be an expensive job and hard to justify given the amount of use made of them.
As far as MTM is concerned I can't find any reference in the RCME forum but there is a topic on the Model Engineer Forum which suggests that it might not happen but the last post was a while back.
**LINK**
I suppose we shall have to wait and see.
From around 2008 PDF files were created for each issue to send to the printers and these no doubt still exist. Whether it is possible to use these as a base for viewing the back issues remains to be seen. I believe there are ways of displaying PDF filesas images so that they are effectively read only. Also, Pocket Mags presumably have copies too as they will sell you individual issues.. Even if there is a technical solution there will still be piracy and copyright issues.
Colin