This tour used to be one of the ones where a shared bath was a possibility. This was when the Switzerland stop was in Stechelberg in the Lauterbrunnen Valley. The possibility of a shared bath is no longer listed.
To see if a shared bath is a possibility go to the specific tour page.
https://www.ricksteves.com/tours
Scroll down to Physical Demands and open that section. Here’s what it says for the 21 Day tour:
“Our tours are physically active! It's an essential part of the Rick Steves tour experience. On our Best of Europe in 21 Days tour — among other things — you'll need to happily…
- Carry/roll your luggage over uneven pavement (possibly several blocks) and up stairways to reach your hotel, then up several flights of stairs to reach your room.
- Be on your feet, walking and standing, for up to three hours, indoors and outdoors, in all weather conditions.
- Sleep with street noise and no (or weak) air conditioning.
- After orientation and transportation lessons, be able to navigate towns and cities on your own.”
To see a tour that currently has shared bathrooms, go to the Best of Scandinavia tour and look at Physical Demands where you will see the shared bath thing.
This is a wonderful tour! I do recommend arriving at least one day early to the Netherlands and staying as many days as you can in Paris at the end. It did not seem like a long time to me, lol. You are seeing blockbuster sights every day!
I recommend a waterproof rain jacket with a hood and shoes that you can walk 5-7 miles in. Our longest walking days were 10 miles in both Amsterdam and Rome. This was before smart watches so was measured on a pedometer which were not as accurate. The better your fitness level the more fun you will have!
Go!