Guilliman had nothing to do with it. Games Workshop don't work this fast, it took a year to alter the Knight Castellan for example. They still haven't updated the Caladius tanks. Eldar flyers are untouched. An RG list performing well doesn't mean anything when other factions regularly finish higher.
It's silly to increase the points, but at the same time this is still a unit that isn't in a codex and the rules/points are bound to change again.
I see the whole Primaris range as being in beta at the moment so I'm not too bothered. Let's wait for the codex. This unit went up 30, but what if another unit drops 50? Not long to go now.
Primaris do feel very beta and incomplete at the moment (still waiting on that Gravis Captain kit for example), but Guilliman still needs to be fixed in the next book so we can have sensibly priced tanks for a change.