Blimey there are some weird ideas being put around about fuel (I'll get back to weight).
Dumping at the end of a flight is definitely not done as a matter as routine...
General policy (as agreed with the regulator) is carry enough for flight from departure to destination plus enough for a diversion to a nominated airport, plus some other buffers. The aircraft commander can opt to put even more on if for example the weather forecast is crappy but you shouldn't get to destination above maximum landing weight...there's no point.
Also maybe worth pointing out that putting lots of extra fuel over above what is needed for a flight makes the aircraft less efficient, you burn some of the extra fuel carrying the extra fuel which is not a good thing, especially for those who are fans of cheap flights.
As for passenger weighing..I suspect the outage bus in the MSM started rolling on this a few days ago when Finnair announced they were doing a survey to check their assumed weights were still correct...most airlines do similar at intervals over the years but nobody in the media could be bothered to read and understand what Finnair were up to:
https://www.finnair.com/fr-en/frequently-asked-questions/airport-and-flights/why-is-finnair-weighing-passengers-before-flying3267140