Lovely capitalism, many investment funds are like sharks hunting for prey, I have seen this same story over and over, across many industries.
It's a common tactic, amongst many others of dubious nature, to find a company with a captive market that they believe can take being price gouged, buy them out and then radically hike the prices. Everyone up in arms but nothing you can do but cough up and take it without lube, sorry folks but Oaktree has got you over a barrel.
Unfortunately it's become a prevalent way of doing business, focus on short term profit taking, long term repercussions of price gouging the customer will be someone else's problem/who cares the company has been milked already.
They must have seen a goldmine when they discovered how widespread and deeply embedded cPanel was, for interest sake have they given any motivation for the increases?