Any RMD required of the 401(k) must be completed before any other amounts are permitted to be rolled over from the 401(k). Rolling the money over to a traditional IRA will not change the total amount of RMDs from 401(k) accounts and IRA accounts combined, but it might make managing your retirement accounts a bit easier. As Bsch447 mentioned, you might have different investment choices depending on the account holding the retirement funds, so that would be the main consideration. A financial planner might be able to help with that, but beware of the motivation for such a planner's investment recommendations if the planner is gets paid via commissions on the investments.
Another thing to consider is whether or not it makes sense to convert some portion of your retirement savings to Roth where you might pay more tax now but less tax later for a net overall reduction in tax liability. With substantial amounts of tax-deferred savings, it can require careful planning over the rest of your life to realize the deferred income in a tax-efficient way.
