This is not possible! The rule is clear: in every EU country you can use your mobile phone under the same conditions as in your base country (with some minor exceptions mostly for mobile data). Telcos not obeying this rule will be fined (or may even lose Radio Frequency License if not willing to obey).
I'm not completely sure that's true – it's possible that an operator might simply choose not to offer roaming at all with their basic plans, requiring an add-on to allow roaming.
But the op said that telcos found a way around this, implicating that plans were changed to exclude roaming. But I haven't heard from anyone in UK or Germany who had roaming taken away.
So it remains possible that a company will try it at some point but it will likely be very rare.
Would anyone get a plan without roaming? Looking at the size of European countries that would be unthinkable for anyone I know. Unless it's.. free or something. Maybe then.
