re-hashing one of my favorite points: A word means what you put into it...if you use the word 'tradional' it needs to have a meaning other than just 'old' or 'common'...or whatever. The word was created, as greg stephens suggests and argues clearly, to refer to the various inputs from numerous sources and its subsequent 'recognition'.
Being 'old' can be one aspect of 'trad', though it is not always the case.
If, as you say, Les.."more and more research shows" that the meaning is being diluted, this seems to indicate to me that many people are just being lazy in their thinking and paying little attention to ;meaning', not that 'meaning' has changed.