Excuse me I have a question, Im a programmer and there are definitely ways to keep the current header graphic dunno what dev told management this but he is lying (and lazy). Why not keep it?

You can
a) use an opt-in approach (like reddit)
b) have both options, either use logo/text or header graphic
c) have it display as header background with a transparent color overlay

If the problem is the graphics are being moved to another server and the future server will not have much space for user graphics you can use a CDN service (talk to imgur they'll do it for a link back )