As we have very little info on this new app it is had to say when they release updates.
From what I see it is about 10 MB more data that users get for each map they reinstall.
The only way to see when a real update it shown when you start TomTom is to wait and see.
Seeing that the last was in March.
When user's delete what they have and reinstall new you get the latest but it could be much more than 10 MB if you wait.
I know from the past it you had a stand alone unit and you used the PC updater there was always updates that user's add.
You could use them but for the official you needed to wait to get the updates.
I bet if you did this 30 days from now and deleted the maps and reinstall them they would be bigger again by another 10MB.
I just turned on my wife's phone and started TomTom.
She gets a notice of new map updates for Belgium map.
Spoiler: Map update
It goes from 225MB to 300MB
Now Smeus did a manual delete and update for Belgium map and went from 220MB to 244MB
So waiting does work with update notices........
And the maps are bigger also........