I've flown FRA-ICN and ICN-SIN in Y in recent months and by and large, the service was the same. However, the service can sometimes be inconsistent and I also experienced some of the changes you mention, sol95:

- Meal menus: Sometimes they hand them out, sometimes they don't, even on the same route. I can't make out any rhyme or reason to this
- Food quality: The same as always
- Wet wipes: Can't remember, to be honest, but you may be right
- FA friendliness: On those routes, I haven't noticed any difference thankfully
- Personal greeting: I still have been getting the greeting, but sometimes they forget or are too busy on a full flight
- Toothbrushes: Yes, I noticed this as well. The pre-coated toothbrush kind of weirded me out the first time, but oh well, it seems to work.