Actually I also have a lot of dead coins but until now there has not been a single one that grows back, if there is a dead coin that grows back and has a road map then that can be a consideration for us to support again but must first look at the details so as not to feel disadvantaged again.
There are too many projects in the market to start paying attention to projects that makes a comeback, because I didn’t not know what killed them in the first instance, and there is no assurance that whatever they did to kill the first project as being fixed and there is no guarantee also that they are not coming to scam the second time, so for me, I would not pay any slight attention to them.
Like you, I already have a handful of bad coins already and I would not want to just keep holding these coins that are not trustworthy, rather than investing in a project that is making a comeback, I think that I will invest in already existing project that is listed among the top 10 coins or I just keep investing my money in bitcoin already because any money I have in bitcoin can never be a waste.