Sorry, but it's unlikely this will change any time soon. For the foreseeable future, we plan to concentrate on widening our support for open protocols and standards. We don't plan to concentrate on supporting proprietary APIs that are under sole control of a single corporate entity.
If you need to use some parts of MS Graph API on a legacy platform that is not supported by MS Graph API SDK, our Rebex HTTPS library could be easily used to achieve that with a bit of custom code. We can also help implementing a library for this on a custom development basis - see https://www.rebex.net/support/services/
for an overview.