I am skeptical - need more evidence.
I am not sure how much conclusions you can draw based on the 33RPM recordings of musicians to comment on their vidwat. I think all of them were very short in nature quite contrary to the concert format of 19th century. In other words, they could have been "packaged" for release in 33RPM. Also, there were also slow-paced musicians like Tiger then. Not everyone went express speed all the time. I also did not think Musiri went super-fast (?). Also we do have regardings of vINa dhanammal - they are in the form of music we love today. Now even though they are probably from a later time - I would highly doubt that she in particular would have altered her style "as per modern times".
Besides do you realize what you are saying would mean? The so call prized gamakas of carnatic music in the form that we cherish today
(and i may add puff our chests and thump our chests at the drop of the hat - you know "being most evolved, most sophisiticated, etc. etc.),. is really something that developed *just* 50 years ago.
And thus in spite of an evolved theory and notations of SSP and mentions of gamakas earlier, to our palette today "it is very bland". Damning indeed - isnt it
But not because of this, IMO, things just does not add up at all.
I do not disagree that music changes/evolves - but to say that the music in the 19th century was "flat" and minimal gamakas (compared to today) like some interpretation of SSP today suggests, is a huge stretch. I like a lot more evidence. For example, how come all musicians suddenly started performing with gamakas in 50s (or event 40s, 30s)? Who was the torch-bearer of that style? Why didnt his/her "unique style" stand out so much that people didn't know of it? (newspapers and media were around then). And there are people alive today who were alive then or even alive 20 years ago. How come this went "unnoticed"?
To reiterate - just does not add up at all. If one applies Occam's Razor - the conclusion is our interpretation of SSP is not entirely accurate that the notations do not reflect all the dynamics of the gamakas.