That has nothing to do with being busy, even if your busy you are running a project and people are expecting you to at least show some presence. I was like you once, waiting too long and ending up losing my investment entirely.
If the dev was working on the new platform for the past 3 days, he would be using his computer and he would have logged in at least AT LEAST once.
So it comes back to this 2 choices
1-the dev dumped all his coins on the latest pump and now he plays shady games disappearing while trying to buy back at ridiculous prices to get another round of pump going on.
2- Or the dev dumped everything he had and he is just gone.
Not waiting any longer on this ridiculous behavior.