Advent Calendar 2019: Day 25

Falathi:  If I may: this is true that rarity of a tank can be defined in basically two ways: either amount of tanks available on the servers, or how seldom it is offered. However, in any case rare tank would be, in the first place, a vehicle that cannot normally be obtained and was never available in large numbers - and one that is not very popular alltogether.  As for happiness - I can completely agree. Noticing if people are happy or unhappy is one thing, but accurately defining why they are unhappy and how to address it is another thing altogether and can be tricky. 
As mentioned above - people can feel disappointed, but their disappointment can be caused by different things and can`t be fixed with one, simple move.