Is the "Maintenance required visit your dealer" screen a notice to change oil?

Not necessarily. Oil change interval is 10K miles, but Toyota recommends tire rotation and other checks every 5K miles. Hence, the 5K maintenance reminder. So, this reminder comes on every 5K miles since it was last reset. It's up to you to know whether you need to change oil or just do the tire rotation.

 

As far as I know there’s just the one simple mileage-counting (maintenance) alert, telling you basically 5k miles have gone by.

The maintenance specs are outlined by Toyota USA in the Warranty and Maintenance Booklet. If yours is missing one option is to download a pdf version, and one option for doing that is the Toyota Tech Info website (just Google).

The official Toyota USA maintenance schedule is event-by-event format, making it absolutely impossible to see the various maintenance frequencies. I’ve cobbled a spreadsheet summary, table format with miles/months columns and maintenance rows. On the road right now but can post later; tonight if I get a chance.

 

2022 Owner here who has actually read the Owner’s Manual. Just the one screen and easily reset following the instructions in your Owners Manual. If you don’t have one you can go to Toyota.com and follow the menus to download one. You will need your VIN number. You can also download the Maintenance Schedule.
I would recommend getting them so you can find the information you need easily and not have to wade through a lot of miscellaneous information here.
The message comes up initially at approximately 4500 miles after the last reset and then goes away. It returns at approximately 5000 miles and stays on.
The fact that it came on now tells you that at a minimum it’s been approximately 4500 miles since the last oil change by anyone who knows what they’re doing, including a dealership.

 

BTW and FWIW: To say Toyota recommends 10,000 mile oil changes ignores Toyota’s recommendation for 5000 mile oil changes in several scenarios. The Maintenance Schedule explains that in the often ignored footnotes.

 

The MM (maintenance minder) will pop-up every 4500 miles and disappear once you get moving. After 500 additional miles, it won't clear unless you manually clear it; then won't go away with every startup; unless your reset your MM.
You can reset the MM in the gear option of the MID. Don't forget to back out and reset to your normal display options. Thought I screwed up my displays the first time around - then realized I didn't fully back out of the menu.

Hope this helps

 

Yes, I know but didn't want to over-complicate the answer to the OPs question. And I covered my a$$ by saying "it's up to you to know when to change oil"

 

So, the way of not overcomplicating the oil change interval is to say it is 5,000 miles, unless you can honestly check 'no' on every one of several driving conditions listed in the scheduled maintenance guide.

If you check 'no' on all of them, you can go 10,000, if you want.

 

An important note is that these spreadsheets ignore the footnotes from the maintenance schedule, which can lead to mechanical failures.