Since Uniden has already announced these upgrades for their x36 radios, and then the XT based phase 2 radios, and left the HP2 alone, I doubt it will ever get such an upgrade.
However, nobody knows what Uniden knows and Uniden does not pre-announce what they are doing. Bottom line... nobody can answer your question.
For my 2 cents, I own an HP1 and two HP2 radios. Have both x36 radios and most of the others too, but never bought Provoice or DMR upgrades for any of them.
My impression from the forums is that even though the Uniden DMR version is more functional than Whistler, it's not a particularly good process.
For my money, the Extreme Upgrade for the HP1 and HP2 are much more useful and robust. Has features that visually and in some other ways outperform the x36 radios.
The best display in the business, and very easy to read while mobile. GPS capability also excellent for mobile use.
The HP2 has the same digital decoding hardware as the x36 radios. On some systems it decodes voice better than the x36 radios.
With or without DMR or Provoice, both of which have very few applications where I live, with very few things I would be interested in scanning, the HP2 is a very solid radio.
536/436/ws1095/996p2/996xt/325p2/396xt/psr800/396t/HP-1/HP-2 & others