@Marian31, welcome to THS Forum. Kudos on extended housesitting and European visits 
. For first time in few years we’re not actively searching for Schengen housesits so curious to read your observations.
We find that Schengen area pet parents, relative to Canada and UK peers, tend to post listings much closer to housesit start dates. So we’d guess that summer Schengen listings are probably still limited.
How THS Marketing team works, priorities and writes content seems a mystery. For what it’s worth, a year ago then we tried to encourage THS to increase marketing spend on Schengen area (weblink below). We have not observed any incremental listings or marketing.
Given world developments then it would seem smart for a UK-based company not to overly obsess about US marketing. Given extensive THS Forum threads, we suspect that many non-US housesitters (including us) have zero interest in confirming US listings and would dearly relish more listings beyond US/UK.
Wayne Gretzsky: “I skate to where the puck is going to be, not where it has been”.
Happy hunting.