I see it a bit different. I agree with this
Saying it every call in a dash8 - yeah that's unnecessary.
and this sounds sensible as well
you land straight-in approach in a medium wake aircraft. Still air and unlikely your wake will blow away quickly. An ultralight late downwind turns right in behind you and their radio call gives you the impression they may not be aware of wake turbulence. You give them a quick reminder of a non-standard consideration.
Yes I would advise other aircraft if I saw a Kangaroo on the day, bit, I wouldn't tell them everyday that I saw a Kangaroo once upon a time.
Likewise with the flames from the exhaust comment earlier on, yes I would advise some one if I saw it, BUT I wouldn't advise every piston aircraft I saw from then on "caution possible fire in the exhaust" which is the direction some of the earlier posts were heading.