I will always take the side of the actual band themselves = bandcamp. Screw what the label says!!!
I don't get what you mean. It says on the bandcamp that it was first released 2012, and there are reviews that go back to 2012.
It even says on the right hand side:
Quote: Vassafor is Black Metal incorporating various forms of extreme dark music in particular doom as evidenced on self titled MCD/MLP "Vassafor". The 2 song tape from 2010 "Promo MMX" was reissued via Canadian label Serpents Head Reprisal in Jan MMXI. Debut full length "Obsidian Codex" was been released on double LP in MMXII via Parasitic Records.
I assume Bandcamp dates sometimes reflect the date of uploading to the service rather than the physical release. They seem to be wrong rather often. But that's not consistent either, dunno what's up with them.
What does the April 2013 date mean then? Im guessing but maybe it was leaked in 2012 and the actual FINAL PRODUCT was released by the band themselves earlier this year, hence the April 2013 date?
Why are you so fixated on the April 2013 bit? There's no info explaining anything about it and there's two instances explaining of a vinyl release in 2012. There's no reason to assume it was leaked, and if so why would they say it was put out by a label in 2012 and would reputable webzines review a leaked version?
As has been said, it's probably when it was put on bandcamp or an error of some kind.