The latest and greatest

Thanks for the clarification, @willemj

Those of us who have saved years of copies of Stereophile can go back and look at speaker ads from companies and designs long since vanished. And yet Vandies, Maggies, Triangles, and several others are still around in more or less their original config.

Any product line is going to be susceptible to style without substance - or simply to the whims of the market.

I think you have two things going on with the LS50 that are causing them to come up for sale in greater numbers.  First, the LS50W appears to be an improved model...which in many people's minds devalues the original LS50.  Second, the LS50 purchase price new seems to have dropped from $1500 to $1000 https://www.crutchfield.com/shopsearch/kef_ls50.html
which means owners of LS50s thinking of selling may want to sell before the price drops even more.

As for LS50Ws...no doubt that at $2000 there are a lot of great choices and people who bought them are probably a little concerned seeing how much the price of the LS50 dropped.

The LS50s don't do everything perfectly.  In my opinion if you want scale and dynamices, there are better choices at $1000...but if you have a small to moderate size room and you want tonal purity and great imaging, the LS50s remain a great choice.

The LS50W (for Wireless) is an active speaker, so you get an amplifier in the bargain.

Yes and now that the ls50 w is $1200 more than the non amplified version it may not be perceived as such as bargain.