Massive topic. A few starter points;
1. the scene is going to get more saturated. In all forms. The 3 most popular forms; Rooftopping, derping, and metro, in particular. The nature of urbex giving fairly instant results, how it can create clout, how it is addictive, and how people are getting more bored all contribute. Considering how many people there are in the world, and how easy this hobby is, I am shocked urbex isn't more saturated than it already is. The UK artistic pubic hair sculpting scene is probably as big as the urbex scene is.
2. Contrary, places are getting scarcer. The saturation threshold for urbex is low. Places are somewhat finite, despite there being loads. But there are barely more than a few truly epic finds per year now and formerly epic sites are continually disappearing.
3. The 'authorities' are getting a weird mix of more fed up with it, yet more desinsitised to it. Urban developers in London for example are paying for injunctions on skyscrapers under construction because they're sick of rooftop kids running around their building site, yet they are less surprised and in shock/weary when they do. This paradoxical balance will only get more fervent over time.
4. I think at some point in the future, i can't really predict a timeframe, but 'money shot' in the context of 'urbex media' will lose its 'epic' appeal. Rooftop posing shots of the London skyline will no longer wow the general viewer. They will become boring. Perhaps then people will start to revert to investing in uncovering local heritage?
5. Tatooed hippie girls are going to keep stripping off on old mortuary slabs, blokes are going to continue taking photos of them, and hashtags are going to keep abounding on social media. Some things in life are constant.