Tech might advance but lost DNA is lost DNA. You might be able to guess at sequence, but once gone, it's gone. Extracting intact genomic DNA, even from living cells, is difficult, not to mention sequencing errors and artifacts are common and happen all the time. Even for singular genes, we sequence at least 5 times to make sure things are correct. Fun day dreams though. If you want to see real and sophisticated science, I could upload some crap on to youtube.
It's more feasible, by that time, to make custom organisms, rather than bring back lost ones.