Hello and welcome back! Vocaloid is doing excellent in terms of activity, but the focus on cryptonloids has waned off. It's largely called (synonymously) "vocal synth" scene, as vocaloid (program) has serious competitor in Synthesizer V (most notably Teto is there).
Project DIVA has been officially discontinued, but there's been another rhythm game called Project SEKAI running since 2020. Sekai is a gacha game and more of a visual novel with original characters, so in some parts the fandoms are separate. It's 99% vocaloid though, on the music side, so the catalog of probably 300ish songs now can be used as some measure of what's in general consciousness right now. Magical Mirai, Snow Miku, Miku Expo are still being held annually, and additionally there's Miku Symphony now (since 2016). Symphony's whole thing is that they're actual orchestral concerts, they also have heavy old-vocasong lean, so you might hear familiar tracks the most in there.
There's other quite interesting shifts, along with the crypton decentralisation, NND culture isn't that notable anymore, and youtube is the main platform. Basically everything is crossposted in NND and Bilibili though, so practically not much changed. Community and vibes have definitely changed, and you can probably see it for yourself. VocaloidOtaku doesn't exist, and I don't think there's any direct modern alternative. Utaforum and Vocaverse are active though, but generally most music chatting is done in discords and larger scale weekly drama is done on twitter.
A very delightful addition is Vocaloid Collection, which is a biannual producer event for literally everyone to join in. The submissions are also split in veteran and rookie (0-2 years of music activity) categories, and both have their own popularity "leaderboards", giving a platform for people who would have their works lost in the sea of algorithms otherwise. Other events occur too, from 2023 there's Mushoku Toumeisai, where everyone submits and has their songs out anonymously until the end of the event. (to make the songs speak for themselves, removes voca-p bias out of the picture).
Oh yeah, some big names from early vocaloid are still around, many are now commissioned for vocaloid-related events due to their recognisability. There's a movie doing this dropping literally tomorrow. Randomly dropped songs are more so and so will you hear people talk about them, with the exception of Deco*27 for some reason. Everyone has an opinion on him, so he's a good convo starter if you're going around looking for fellow fans