Not at all. I have an intimate knowledge of how Semmangudi sang at 80. This recording was in his prime, to be precise 1962-66. The violinist is most likely Tiruvalangadu Sundaresa Iyer in his last days (from the way he's playing) who left the world in 1966. That should give an idea of the time frame. The mridangist is probaby Vellore Ramabhadran.
I agree there's no D2 per se anywhere, although the "sound" or swara of D2 is there when N2 is articulated in a phrase in anupallavi "sētu bandhana sura pati etc" as S N2 R2 etc. That N2 certainly has the "sound" of D2.
Here it is at 3:38:
https://youtu.be/zLuQIAjWH74?t=217
Again in the charanam "sura taru sumamula", the highlighted phrase is articulated as the "sound" or swara of D2, athough the swara is of course N2.
Here it is at 7:13:
https://youtu.be/zLuQIAjWH74?t=429
If you just hear the sound of the recording, as from a distance you sometimes listen to nagasvaram wafting through the air, without actually following the melody, but hearing snatches of phrases and sounds, you could catch a D2 at these places.