The current certification requirements for the Microsoft Office Specialist: Expert (Microsoft 365 Apps) do not include Access 2019 Expert as an accepted qualification. The requirements specify that candidates must earn an Associate certification in three different programs, with at least one being a Microsoft 365 Apps exam, and pass two Expert exams, which must include either Word or Excel from Office 2019 or Microsoft 365 Apps.
While your suggestion to include Access 2019 Expert as an accepted qualification for the MOS Expert certification is valid and could potentially enhance the breadth of qualifications for candidates, any changes to certification requirements would be at Microsoft's discretion. Currently, Access is not listed among the options for the Expert qualifications in the context provided.