Only 30 Backfires will be modernized to M3s; the TU-160 is "Blackjack"
The Backfire, or Tu-22M3, has two 25 ton thrust jet engines called NK-25s.
It is very similar to the 25 ton thrust NK-32s that the Blackjack has four of... similar size, similar weight, similar power, similar fuel consumption.
The upgrade proposed over a decade ago was to upgrade all the Tupolev bomber/cruise missile carriers with the same avionics, the same radar and in the case of the Backfire and Blackjack jets the same engines. The Bear also has a jet engine in the form of a turboprop, but there were no plans to change that.
The fact that they are going to upgrade 30 Backfires to Tu-22M3M level does not mean they will get rid of the other Tu-22M3s.
The MiG-31K is not the latest upgraded version because all it will do is launch Kinzhal for the VKS.
They are testing the Tu-22M3 with the Kinzhal too, and one suspects if that is successful there would be no need for this Tu-22M3M upgrade for any aircraft the VKS might use.
If pak da is suppose to be a new tu-160 then it is too much to replace also tu-22 with it. Tu-160 was already expensive. Pak da will be more.
They need a new tu-22 replacement.
The PAK DA will replace the Tu-95 and the Tu-22M3.
To replace the Bear you need a modest payload (9-12 tons of cruise missiles) over a very large range (12K kms or so).
So lots of extra fuel plus some cruise missiles.
For shorter range missions the same aircraft can reduce the amount of fuel it carries and carry more weapons, so it would replace the Backfire by having a larger payload of weapons over a shorter range... though the latter is not so important as it will have inflight refuelling anyway.
The TU-22Ms have big upgrading potential for decades to come.
Avionics that allow precision bombing with dumb bombs means it is a cheap effective system for the COIN wars most large countries and superpowers seem to get involved in.
The only thing the retirement of the Tu-22M fleet would accomplish would be to please the USN...
Exactly... its lower flight speed and ceiling compared with the MiG-31K reduce the performance of the Kinzhal, but being able to fly 2,000km and to operate there for a few hours before launching an attack and returning home adds a new dimension to its capability... and having to send 4 Tu-22M3s with 16 Kinzhals instead of 16 MiG-31s makes a serious difference in costs and capabilities... of course if you want the extra performance you could always send some MiG-31s to lead an attack with high performance kinzhals and some Backfires to clean up what is left...
The potential is enormous with the Backfire... you could use it as a high speed inflight refuelling aircraft for Su-34s... put an enormous AESA radar in its nose with dozens of heavy long range air to air missiles from R-37M to S-400 and S-500 based missiles...