When the switch to relevancy was first made, a few months ago, the items from my shop that ranked the highest under relevancy were often those that had been listed a long time (and, in many instances were items that I hadn't tried to optimise the titles and tags for! Go figure!!)
However, i checked again recently, and my most recently listed or renewed items seem to be ranking the highest under relevancy now. So recency definitely appears to be part of the relevancy algorithm - and much more so than it was a few months ago. I will be keeping a close eye on this to see whether the trend persists - and whether it is worth spending a sizeable amount on renewing each month (I feel the jury is still out on this one - particularly as the relevancy algorithm still seems to be in a state of flux).
I suspect that etsy want to continue to generate revenue from constant renewing. Perhaps the Search Ads haven't been the success they had hoped for - and they are are looking for alternative ways to recoup the revenue that they lost when the switch from recency to relevancy (under Search) was first introduced -- and fewer people renewed as a result