I doubt they would need additional investors to compete/win League 2. I imagine the club is bringing in a ton of revenue now that nobody south of the Championship can match and wouldn't require much in the way of infusions.
I just looked up someone's estimate of values for current League 2 clubs and the range is only 1.4 - 9.2MM Euro (not sure why it would be in Euro so take those numbers with a huge grain of salt) so it's not like they would raise a ton of money by selling a share at anything close to League 2 or even League 1 valuations (5 - 23MM Euro).
I just looked up someone's estimate of values for current League 2 clubs and the range is only 1.4 - 9.2MM Euro (not sure why it would be in Euro so take those numbers with a huge grain of salt) so it's not like they would raise a ton of money by selling a share at anything close to League 2 or even League 1 valuations (5 - 23MM Euro).