Since Blizzard doesn't provide us with any information beyond the vague and often incorrect in-game tooltips, all testing is subject to players. The community has only begun to understand the power of Manald Heal and there are still many mysteries to be solved. I urge you to follow this thread.
D3Planner is a fan-made tool and can only implement data as the playerbase provides it, and especially for complicated mechanics it might never be entirely accurate for the simulation. I wouldn't be surprised if there are some people who have figured out things about MH that the general population doesn't know; based on D3's history, oftentimes a new build or new insights appear 4-6 weeks into the season (S1 DH, S1 support crusader, S4 SC monk, and many more) or even 2 weeks before the end (S3 Hydra wizard). So please don't assume that "everything has been figured out"; there's always the possibility that tomorrow the entire meta will change. And that change will only come from in-game testing, not by simulating numbers in a fan-made offline tool.
No, there has not been a banwave. The Diablo 3 website API is simply bugged and sometimes omits names, it's been that way for weeks. Known bug. Check in-game leaderboards for accurate data.
Ok, somehow i thought d3planner would read its values and formulas out of the game files. I guess i read it somewhere in one of those places in the internet ... Thx for clarifying this
Besides that, I am totally aware of the fact that d3planner simulations are not to be taken too seriously, however it can sometimes help to get some feeling, especially if you compare small variations of a specific build. Sometimes I have the impression that figuring out certain game mechanics has become a real part of the season progression, apart from the more traditional ones gear and paragon
I do not believe that "everything has been figured out", to continue your point instead, we see at the moment that new insights can even pop up 2 seasons late with the iteration of the gen monk in the 4man group meta (S7: fire+area dmg, S8: fire+attackspeed, S9: cold+attackspeed).
The fact that the official website is flawed like that can really make one think about the status of the game...
Yes, D3Planner takes its knowledge from the game files *when it's possible*. The creator regularly datamines the most recent patches, see here. However, having access to all the data doesn't mean you know how they all connect; all the server-side calculation and mechanics are hidden because they're not in the client data files.
The status of the game and the flawed API have nothing to do with each other, though. The API is just not a high priority on Blizzard's list, sadly.