Of course it is - welcome, even.
And yes, it's difficult to predict the future and we should be wary of over-simplifying any of this.
That said, so long as the UK is an EU member the 'dynamism' of its politics are limited with respect to discrimination within fee and funding arrangements.
Postgraduate fees aren't directly regulated by government and universities are free to raise them. What they can't do is charge an EU student any more than a UK student - and there's nothing the government can do about that.
The situation with loans is similar. No future UK government can remove EU students' entitlement to public student funding whilst the UK is still a member. It can alter the postgraduate loans scheme itself, of course, but it can't discriminate within it.
By the same token, EU countries could introduce or raise fees, but they wouldn't be able to charge extra to UK students except in certain circumstances (the Czech Republic, for example, does charge - but only for courses that aren't in Czech).