Yes, there are such a trains. The one and only model which doesn't have toilets is NS Sprinter Lighttrain
They are replacing original Sprinters, which do have toilets.
These are commuter trains, thus generally not intended for long distance travel. They do have some quite long routes (eg. Lelystad—The Hague), however for that kind of distances there ...
With regular NS trains (intercity's, sprinter's and stoptrains) booking in advance does not give you any discount. If you would travel with a NS HiSpeed train this could be the case, but there's no direct HiSpeed connection between Eindhoven and Amsterdam, so it's irrelevant to your journey.
There's a direct train between Eindhoven and Amsterdam Central ...
There is catering on some local Intercity trains as well. It used to be served using small trolleys, but a few years ago they switched to backpacks and added more brands like Starbucks.
The NS is not providing structured information about where they are.
"On Intercity's throughout the Netherlands and on the NS Hispeed train ..."
It's true. But it's not so much the short distance trains as the slow trains (which you typically would take for short distances).
I haven't seen these 'peebags' myself, but apparently, there at least was a plan to introduce them (in Dutch):