My questions is that ' is there any possibility that some point in time in future BTC community might decide something which can retrieve this lost BTCs?
No.
Lost coins only make everyone else's coins worth slightly more. Think of it as a donation to everyone.
We can say that lost bitcoins are like token burning in deflationary tokens. Where token burning reduces the circulation of coins and that makes token demand to surpass token supply. There are 21 million bitcoins that will be ever generated, if out of those 21 million let's say 5 million are lost forever then we are left with 16 million bitcoin only.