I read some old threads about lost Bitcoins ND this question has been on my mind ever since
If the lost Bitcoins were for instance recovered will the price of Bitcoin drop because in theory it would affect the amount of Bitcoin in circulation which will lower it's price . I saw in those threads that lost Bitcoins are considered a donation to the Bitcoin network. so if my theory is correct then we should be happy those Bitcoins were lost.
For any situation one is in, we will have the benefitted one and the affected one. A person who lost his or her will never be happy it happened, but as for the Bitcoin network, it will be benefitted one as you said.