I think that the meaning of "indie developer" has changed throughout time. Back when I first started programming the people around me considered indie teams to be a development team that was not associated with a publisher. The "indie" part came from being independent of any 3rd party. This was before everything went digital however... Now anyone can publish a game without a large amount of capital and they're not forced to depend on publishers.

I've also found that many people define "indie" differently to being smaller teams, lower budget teams, teams without publisher influence, ect...

40 minutes ago, Scouting Ninja said:

For example PlayerUnknown's Battlegrounds was considered indie but Fortnite never was. Yet both were made by registered corporations. PUBG corporation and Epic Games. 

Considered indie by who? PUBG (the company) is directly owned and funded by a publisher - they are not independent at all and never were... "PlayerUnknown" himself started out as an independent mod-maker, but the PUBG company has always been publisher-controlled.
Epic did literally start out as a bedroom programming hobby, so does have indie beginnings! However they very quickly started making games for publishers such as EA, and Epic are now 40% owned by a publisher, meaning they're no longer independent. Epic's owner (Tencent) also publishes PUBG in China  

20 minutes ago, Rutin said:

I've also found that many people define "indie" differently to being smaller teams, lower budget teams, teams without publisher influence, ect...

^ bold bit is "independent", italic bit is the "indie spirit", as in Independent film or Independent music.

This is why I said the meaning has changed over time.  Many game studios are throwing on the "indie" tag just because they're small, not necessarily independent.

I will always consider "indie" to be independent of any 3rd party. I think many studios are miss-labeling what "indie" actually stands for, which is being "independent".

2 minutes ago, Scouting Ninja said:

However these days there are lots of indie games with publishers; The Banner Saga is one that pops to mind. There exists a lot of small indie publishers, who publish indie games

Yeah every game on steam is literally in a publisher agreement with Valve   The difference is that Valve doesn't fund you. The banner saga wasn't funded / controlled by their publisher. They made the game independently and then published it (via a new, small, "indie spirit" / non-mainstream publisher). On the other hand, if a publisher funds your game up-front and has control over the project, then you are quite literally no longer independent in making development decisions -- which is the traditional business model.

2 minutes ago, Scouting Ninja said:

As of yet I have never seen a Massive multiplayer game that is still in full control of the original developers. Would like to try one if someone knows one.

I personally haven't seen it either because of the amount of money required to release a profitable MMO. Hiring the amount of staff alone regardless of server costs is very high.

This is why it would make more sense for a smaller team to just make an online rpg and expand as profits come in and the demand requires. Going full blown MMO from the start without a budget isn't a wise idea.

11 minutes ago, Scouting Ninja said:

As of yet I have never seen a Massive multiplayer game that is still in full control of the original developers. Would like to try one if someone knows one.

A friend of mine made Wander MMO, but they didn't make any money to continue post-launch development and then got shut down by CryTech's lawyers: http://massivelyop.com/2017/09/04/exploration-mmo-wander-quietly-died-and-almost-no-one-noticed/
FWIW they kept costs down with a P2P network architecture, and used government grants to fund a lot of the higher quality visual content.

There's probably plenty of games of this kind of scale -- designed as an "MMO" but never actually getting more than a few dozen concurrent players!