Your motherboard is a proprietary board produced by Dell for their own case. It’s an OEM part that will probably not fit correctly in your new case completely. That motherboard does not follow the universal ATX, mATX, etc form factor.
I say completely because some of the mounting holes may line up inside of the case and you may be able to mount it albeit with some mounting points unpopulated. That’s fine since not every screw is required to hold a motherboard in place.
The only way to know is try it when you get the new case. Just be prepared for an awkward fit and the possibility of it not fitting at all.