It's also possible that the answer could somehow involve Q's seemingly forgotten son episode "Q2," Q Jr. (Keegan de Lancie) was as equally mischievous as his father and could be connected to this new Q in some way that isn't yet apparent.

Source: https://screenrant.com/star-trek-legacy-picard-q-alive-how/

Much like Leonard Nimoy and Spock, Q and John de Lancie are almost inseparable.

Source: https://www.cbr.com/star-trek-the-next-generation-q-real-life-villain/

Q (John de Lancie), 's omnipotent being has appeared across multiple shows since his debut in the 1987 pilot of Star Trek: The Next Generation.

Source: https://screenrant.com/star-trek-q-every-tng-voyager-picard-appearance/