What didn't become clear until about a year after mk3 launched was just 'how big' theme forces would become. Nowadays, everyone plays in a theme force. Although you can play non-theme if you want to get a specific combination of models, the benefits of playing in-theme drastically outweigh the drawbacks.
Also, most themes only allow up to one Merc/Minion unit and one Merc/Minion solo. This has decreased the use of Mercenaries & Minions in other Factions.
There have been 4 key changes that have affected how people play the game and design army lists:
CID is a PP-run forum separate to their main forums, where every now and again they have a 2-week window where they ask players for feedback on new models about to be released, or existing models that are about to be errata'd. (The set of models would nearly always be related to each other, ie the new models coming out for a theme force plus a few legacy models that also fit in that same theme force.) Then they close the forum, run about another month of internal testing, before all the releases are made “live”.
At “peak CID” they were happening about once a month (two weeks on, two or three weeks off), which caused a bit of burnout for both players and developers. At the time of writing (2019.06) the CID process is on hiatus, and we can expect them to occur at a more reasonable pace when they do resume.
CID can cause a bit of a weird play environment on game night because …
At the end of mk2 PP closed down parts of their forum; General Discussion and all the Faction-specific subforums are no more. In the years since, players have migrated to a mixture of Lormahordes, Discord, Facebook, and Reddit. There has been a bit of community splintering as a result.
Around the same time, PP shut down the Pressganger programme (the mostly-volunteer-run recruitment/marketing/tournament-organising group). They shut it down because another game company with a similar programme had a lawsuit made against it and PP didn't want to be in the same boat.
PP has moved to a digital-only format. In Mk3 they intended to release “Command books” for each faction followed by “Theme books” for each new theme, but not enough people were buying the books (why would you when the rules are free) so they stopped producing theme books and moved the “theme content” into No Quarter Prime.
But not enough people were buying the monthly No Quarter magazine so it was briefly discontinued, then came back as a once-every-3-months No Quarter Prime, only for that to get discontinued as well because people still didn't want to buy it.
The current plan (as of 2018.11) is to put that sort of content on to their online '[https://privateerpress.com/community/privateer-insider Privateer Insider]'. The Insider is a series of articles which are a cross between a blog, and news announcements, and “behind the scenes” articles, each written by different staff member.
'Black Anchor Heavy Industries' is the name of PP's direct-order only range of models that they started in 2017. BAHI models can only be purchased from PP's own online store (or bought 2nd-hand).
Don't be (too) alarmed, not every new model is BAHI. BAHI is 'only' used for huge-based models, and it's not 'every' huge-based model (just most of them that have been released since 2017).
'Special Order Models' are older models that no one really buys any more. As of 2018.04 they have been removed from regular distribution and instead they're “special order only”. Unlike BAHI, local retail stores can still get a hold of them (they just need to order them from PP instead of ordering them from a distributor).
'Mini-Crate' is the name of PP's subscription-only range of “bonus” models that started in 2017. They're not new models, they're alternate sculpts of existing models. They're mostly mercenary or minion resculpts. You sign up for a 6 month (or 12?) subscription, and every month a new limited edition sculpt gets posted to you. Plus one bonus one for when you first register.
See also
Several things happened more or less simultaneously, not long after the [Infernals] Faction was officially released, and most of it was tied to the release of the new campaign book, [Oblivion].
2019.08 “Blended Themes”
2019.08 New model “genre”: [Archon]s
2020.02 New model “genre”: Super Juniors
2020.02 Blended theme