With an indie dev that does low budget stuff, but lets you buy some skins or a soundtrack for an extra few quid? Absolutely.
With a big company like Blizzard? Not a chance, the competent dev's can quit their jobs and form studios in the same way the E33 guys did after leaving Ubisoft. I'm not "tipping" bloated nonsense hires in huge companies that have no talent, they can go apply to McDonalds for all I care.

Id' be so embarrassed if people tried to tip me for something I get paid to do already, I'd insist they just gave it to charity.
Which incidentally is something I've told all my family to do next year for Christmas. I don't need anything and there are plenty who do.
It's all a bit parasocial ennit.