If the operators don't charge (as permitted), it's as if the old rules still apply.
I can't believe the fuss the kids are kicking up over roaming charges. Firstly, your phone bill simply isn't that important, but secondly, there's no reason why it'd have to increase - I use my phone freely and without charge in 71 countries and there's only 26 in the rEU.
http://www.three.co.uk/Support/Roaming_and_international/Roaming_Abroad/Destinations
Unless someone is seriously going to suggest that all 71 are as a result of trade deals that many of them don't have with the EU, which won't be the daftest thing a remainer has posted here all week, then it's hard to see what all the fuss is about.