My impression: Sounds like they widened the playlist a little to accommodate some older but safe hot AC artist/titles. My guess is those titles were probably tested in advance with some call-out research.
From my experience running a 60 person research operation I can make some observations:
First, music testing has changed dramatically over the last six to eight years. No longer are "Auditorium Music Tests" done in hotel meeting rooms or community centers. A local research recruiter or a phone bank recruiter provides the proper number of people to do an online music test where they hear the songs and score them. There are very few in-person tests, and the pandemic likely ended that forever.
Generally, an online test will look for about 100 persons, give or take. They will do multiple "sessions" of several hundred songs and might do a total of 500-600 in what might be a normal format test, and up to and over 1000 in a variety format test or a test for a "new" format where the operator wants to cover everything.
A phone test might still be used for currents / recurrents but that methodology does not work for more than 25 to 30 songs at a time. Currents, at better stations, are tested with a recruited panel who does 25 or so songs online every 10 days or so for perhaps 6 to 10 total tests before being replaced. Often a phone bank will find the recruits and handle the verification and data processing with their own software or Cornerstone's product. Hooks may be done by the station or by a hook provider.
So, my suspicion is that Lotus has a "safe list" that they found works in its other markets or which they have acquired and they are adding some of that music in preparation for a full Music Test in the many hundreds of song range. One of the reasons why they would not test "a few" songs is that the recruit cost for a small test is just as high as for hundreds of songs. While this varies by market, a recruiter may charge $100 up to around $150 for the recruit and an additional fee will go to the recruit... often as much as the recruit fee (but variable depending on the market... money is worth less in New York City than in Sioux Falls. Then there is a data processing fee as well... so it adds up. Test 200 songs or test 600, it is going to cost just about the same.
Some of older songs could be an effort to spread the demo slightly. That, and there isn't a lot of new music coming out, so if you want to freshen up the sound, you may need to go further down the bench.
Or widen the lens, either in artists and styles or in deeper cuts. The problem is that once the core is departed from, most songs will have widely differing scores among respondents.
Sometimes doing this might also help drive some 'sample cume', to see how many older titles would be acceptable prior to adding talent and imaging. I'd expect a little more early experimentation and tweaking of the playlist before the final product will be unveiled, so those on this board shouldn't get too wrapped around the axle as adjustments and research is conducted.
A new version of the format or even a fine tuning of the old one has to have a full music test. It can't be done in kibbles and bits. One reason for that is that unless you test all songs with the same group at the same time you have "climate variables" such as sad cloudy days and n ice sunny ones that change median scores. But mostly you need all songs heard by the same group so you can do cluster / factor analysis to see things like fit, subgroups with polarization, etc.
That said, the first test I did in the 70's was a gathering in a room of about 15 fans of our music and we played hundreds of cuts and the people did a thumb up, thumb down or flat hand for like, hate, no opinion. Oh, we had beer in a cooler. And snacks. We cut the station playlist from over 1200 to around 400, cut currents from over 40 to about 18. The station had been dead last among FMs in the market and the next book it was an overwhelming double digit #1. So even some amateur badly done research is better than absolutely nothing.
Oh, that test was in a market of over 2,000,000 with over 40 stations in our coverage area.
