For me, the plan.tomtom.com planner now opens with both Chrome and Safari, and now has all My Places and My Routes reinstated. I have two iPhones, both running the same TomTom GO Expert app. Strangely, one phone had all the Places and Routes back on it, but the other phone didn't.
Looking at what was different between the two phones, one phone had MyDrive logged in (with Places and Routes back on there), but the other phone did not have MyDrive logged on. As soon as MyDrive was logged on to, I saw that the TomTom GO Expert app on that phone had TomTom Services > MyDrive un-ticked. But as soon as I checked that on again, all the Places and Routes reappeared.
Dunno if it is something new, but for me, for my Places and Routes to appear on the TomTom GO Expert app, it needed MyDrive logged in, but not just logged in, it has to be logged in on that exact same device.
Anyhow, for now, all my Places and Routes are back on the plan.tomtom.com web planner, and also on My Drive and TomTom GO Expert on both my iPhones. Fingers crossed.