the 4 ohm bridged rating is less than the 8 ohm bridged rating. That would be very strange if it were true.
Yes… you'll also notice that the individual channel into 2 ohms (3750W) is less than the individual channel into 4 ohms (4500W). Not coincidentally, these numbers are exactly half of the bridged rating into 4 and 8 ohms.
Another example of a well regarded amp showing the same "inadequacies", Lab Gruppen's PLM10000Q can deliver 2300W into 4 ohms, but only marginally more, 2350W into 2 ohms. Driving its sweet spot of 2.7 ohms, it can deliver 2700W.
When an amp is bridged, each channel's load is half the total load impedance.
[edit: corrected bridged loads from 2 and 4 ohms… typo]