After revisiting the PRL whitepaper, I assume there is no timeframes in roadmap for PRL either. Anyway team is still delivering!
If I recall correctly, after the mainnet was delayed for a few days or weeks, the team decided that they won't put dates into the roadmap. And I think it's better that way. I'm a programmer and I know that sometimes you come across some problems that you just couldn't foresee and that causes a delay. And then the community gets angry and so on. It's better if there are no exact dates. Besides, in most roadmaps you can see what will happen in each quarter of a year (Q1 2018, Q2 2018...).
I agree. This is a serious approach, since most of the teams whcih are putting exact dates to their roadmaps they then miserably fail to respect them and they end up losing credibility. I don't care how much time it takes for Oyster to deliver all their roadmap. I am just happy if they do it at some point.