Heya, joined the "Sunken Veil train" in the beginning when it was still a "fanwork".
Thing is, much of the development's direction can be attributed to Numerical, the previous lead who has - as you can obviously see - just bailed out of the project in rather spectacular fashion. You can ask Del himself but one can say the communication was "lackluster".
While the game had pivoted away from a "mere" fanwork to an actual "new game", I agree it still contains way too many "original" elements to be wholly separate. That said, much of the game has literally been reconstructed in a new engine so I'd say it's not a carbon copy.
Right now however, given that it's literally the day after and the project is picking itself up, they can genuinely start on new bases given enough time.