I'm still unsettled about this so I've just re-tried the Come to Canada tool several times, amending one detail each time, to see which combination would result in an eligible profile.
Having arranged employment was still ineligible; being 10 years younger, also ineligible; increased funds, same again; having a good second language score, no change; changing my preferred destination, same again.
However, entering that I have one year of Canadian work experience took me immediately to the page saying that I *am* eligible, with a reference number and a link to MyCIC. I didn't need to compete the form before that page popped up - I was considered eligible without the tool asking me for any other info on work experience, funds, number of family members, job offer, age, or education.
Saying I had skilled trades experience did the same thing, just one step later.
Reading the posts from people who (like me) are a bit surprised at finding themselves newly ineligible for whatever reason, I just wonder how many of those are aiming for FSW, and whether the Come to Canada tool is (currently) calibrated in favour of CEC and skilled trades applicants, and controlling the number of FSW applicants in the EE pool?
Note: I'm not complaining - I just want to understand the situation.