you always have to remember that the points are not absolute, they're relative to the points of the first place team. since astralis won the major, all other teams will lose some points.
also, all matches from the legend stage are already in the form category, tomorrows ranking only adds the matches from the champion stage and the points for the lan category based on where the teams finished.
as for nrg, the roster change costs them 20% of their current points. the fact that they went 0-3 doesn't cost them points, they just gained 0 from that last week. losses are simply not counted, you'd see negative points for low ranked teams if that was the case.
as for nip, the only team that finished higher and is ranked lower is ence, so they will lose 1 spot.
as for vitality, they will surpass north and c9 (again, c9 lose 20% because of flusha), but they won't surpass nrg since 9-16th all get the same points.
avangar is nonsense indeed.