Tsuburaya Productions had registered the trademark for a new Ultraman called "Ultraman Regros" (ウルトラマンレグロス). The registration number is T2021-77127. Looking at the time of trademark registration, this could well be related to Ultra Galaxy Fight - The Kingdom.
The correct romanization is not yet known. It could also be "Ultraman Regulus" or "Ultraman Regulos".