No. The X250BT is hardware-limited to 5.2 channels and does not have Dolby Atmos decoding chips. Firmware cannot add Atmos.
A failed firmware update can "brick" your receiver (render it unusable). Do not skip these preparatory steps. denon avr x250bt firmware update
As of early 2026, Denon has slowed legacy updates for the X250BT. If no update appears, your unit is likely up-to-date. your unit is likely up-to-date.