The trouble with labelling any release not on a major label as indie is that some of the people releasing this way may not want to be classed as indie.
A hardcore dance artist producing albums on equiptment in his bedroom or a thrash metal band recording in a garage may not want to be called indie and may be insulted to be classed as indie.
You seem to be narrowing the category in one way and then expanding it in a different direction.
It is up to the individual artist what they want to be called, and for that matter what they consider to be their first album. Their opinions are a lot more important than yours!
It is quite possible that some artists may not want to be classed as indie. The labelling of music is usually from critics and writers rather than artists though. But as artists are the creators of music then their views should be respected.
As I said before a lot of this is about ethos and ethic. Many of the artists on indie labels do so because they adhere to the DIY ethic and want to be able to create music within an ethos which is independent of the major labels. Some artists just see indie as a starting point.
The trade off with indie is that an artist will have much more artistic control with an indie label but will lose potential audience.