If they make a B770 it would be 16GB like the A770, but it isn't cost effective to do so. 3Gb GDDR7 would require a new chip entirely. I think they are going to hold out for Celestial.
Even with the comparable improvements that we can translate from the B580 and the small node shrink, a potential size matching chip might have 30 Xe cores, if you stretch to 32 it would be a bit bigger than a RTX 5080 die. (RTX 5070 die is smaller than a B580 FYI) GDDR6 as well, so they would be in the same boat as AMD, 9070 XT die is only slightly smaller than a 5080 die.
So unless Intel paid for TSMC 4N like Nvidia, or moved straight to their own 18A node, they could launch an expensive card that performs half as well as the competition. So more selling at cost or loss.