Well that's a very dubious argument, from my point of view of course. If we are talking about old music and lossy/lossless format of course it'd better to have a lossless variant, because lossy formats still cut off a lot of information and you can't say for sure what is cut off. I heard the same opinion that it's wise to store the old music in the lossy formats, because "lossy format for lo-fi", however i consider the opposite, firstly as i mentioned before it's better to preserve the original source (tape or vinyl) in digital format with the help of lossless which gives more headroom or guarantee that nothing will be lost. Lossy can't assure that, because it's not his aim. Secondly it's an off topic but I store everything in FLAC, but listen in lossy for the sake of convenience, and because of that I can change lossy formats easily with converting them.
Finally what I'm implying (that's why I've written alll the above) is that even Hi-res (16+/44.1+) can give some advancement: but, Firstly it'd rather be dependent upon the source, music, remaster or original (the issue with harshness) etc. And secondly it's likely that the advancement will be inaudible in most cases due to hearing or hardware limitations.
P.S. harshness can be sometimes related not to Hi-Res, lossless issue but to equipment and production of the music.