Is this assertion true?
Yes, it is definitely possible. Having been away from Manchester for nearly two years, and abroad at that, coming back has been a real eye-opener. There is a real buzz in the air! People are even more friendly and helpful than before, and polite at that! The attitude to the middle-aged and elderly appears to be exemplary, and of course it's a haven for youth and youth culture!
Cultural and ethnic groups seem to be better integrated than in the past. Public transport is a pleasure, and even the local Lidl has improved, but maybe that's due to the influx of Polish workers who seem very keen to please!
As for the famed rain of Manchester, it may rain often, but flooding is rare and you tend to get used to the constant drizzle. It's also very good for the local environment.
Manchester has always had something about it, but now it does seem to radiate a certain ease with itself. Yes, it's not that surprising to learn that Manchester turns out to be the happiest city in the UK.