It was uninspired and felt forced.
They wanted to make him less of a generalist, yet only change that successufully re-purposed Maokai into a specific niche was his passive; this change honestly was needed.
The Q knockup change was... unnecessary i guess? It pushed more CC where it didn't belong.
The W CC duration shift was ok.
The sapling change (aside from the initial full AP cheese) was welcomed as it allowed maokai to jungle again. I'm obviously biased about this, but i appreciated nontheless.
The ultimate replacement, however, made no sense.
The Maelstrom allowed Maokai to do something unique in the game: teamwide damage reduction. If anything, i would have expected the rework to further push and solidify Maokai in this direction. **This is what good reworks do: they expand what a champion already does, deepen his gampleay and add counterplay if needed.** Something i always found enjoyable about Maokai's old ult was the **damage payback**: he reduced the damage on his teammates and stored it whithin himself, waiting to unleash an explosive revenge. Maokai's balance history slowly removed this aspect; it faded away and was slowly forgotten. **Why they didn't focus on damage reduction and payback?** His new ultimate is very... meh. It's there, it's strong, but doesn't really make Maokai less of a generalist. Au contraire, generic vanguard cc ult #36 strips him of that uniqueness the rework was supposed to reinforce.
I belive that Riot had no real idea of what to do with Maokai. They looked at divers, and were turned away form the amount of work they needed. Then they settled on tanks, and started to decide what tanks were problematic. Sejuani was an obvious candidate for a larger scope rework, Zac had some potential with his "sticky" theme, and Maokai was a staple pick in competitive. Having high pickrate in proplay isn't something that actually inspires for a rework, so they came up with mediocre ideas and no direction. What happened with Maokai convinced me that shutting down class reworks was a really good call.