The main issue that I have is that NRE is most likely obliged to offer Tramlink for some journeys because there are still a few National Rail network fares with integrated Tramlink segments. Therefore, planned tram disruptions really do need to be displayed, and it seems there is a genuine problem here, rather than a minor issue with a "nicety" of the NRE Journey Planner suggestions.
I could understand a lack of last-minute disruption information, but planned work for journeys where a (or the) permitted route is via Tramlink does really need to be publicised.
This is equally the case where a cross-London journey requires Tube travel, though in many cases there are alternative Tube, National Rail and/or short walking routes which can be used if "Maltese Cross" journeys are disrupted, so at least that is less problematic in the long run.