Wandrian
I don't know.
If saying it was rushed is grasping at straws, so is saying it wasn't. We don't have any incontrovertible evidence supporting either statement, all we have is circumstantial and anecdotal.
However, I believe more things lean towards it having been rushed than to the contrary. It's just so much. The unprecedented three mimics(by SC standards at least), Elysium & Kilik clearly intended to possess different styles in Story Mode & Legendary Souls(their artwork also depicting them as non-mimics), the unlock method for 'legacy' weapons Mekkimaru/Kali-Yuga/no name, the lack of the majority of the cast even having a mention in Story Mode, the brief biographies & artbook laying out a much more massive story, Odashimas claim that Story Mode was only a quarter complete, Zasalamels SCIV 1P model being on-disc with no apparent changes, Aeon & Dampierre being essentially non-customizable when the character editor is one of their main draws for the casual audience...It goes on. Yes, this is all circumstantial and anecdotal evidence. I think it's pretty good evidence supporting the notion the game was rushed though.
I can't see any reason to plan for Elysium & Kilik to have different movesets than their art intended, to mention Takis return & have indicators she returned(Mekkimaru) without seeing it, to not have 2P costumes for Aeon/Algol/Dampierre, to say characters are important to the story(Viola) & have them do nothing worthwhile, to make the protagonist an unlikable douche without someone else taking center stage at some point, to release an artbook spoiling what would be the rest of the story, to continue development through power outages and nuclear disasters...Yeah sure, you can disregard as much or as little as you want. But as long as you're grasping at straws to say it is or isn't rushed, more points towards it having been rushed than the opposite.
However, I believe more things lean towards it having been rushed than to the contrary. It's just so much. The unprecedented three mimics(by SC standards at least), Elysium & Kilik clearly intended to possess different styles in Story Mode & Legendary Souls(their artwork also depicting them as non-mimics), the unlock method for 'legacy' weapons Mekkimaru/Kali-Yuga/no name, the lack of the majority of the cast even having a mention in Story Mode, the brief biographies & artbook laying out a much more massive story, Odashimas claim that Story Mode was only a quarter complete, Zasalamels SCIV 1P model being on-disc with no apparent changes, Aeon & Dampierre being essentially non-customizable when the character editor is one of their main draws for the casual audience...It goes on. Yes, this is all circumstantial and anecdotal evidence. I think it's pretty good evidence supporting the notion the game was rushed though.
I can't see any reason to plan for Elysium & Kilik to have different movesets than their art intended, to mention Takis return & have indicators she returned(Mekkimaru) without seeing it, to not have 2P costumes for Aeon/Algol/Dampierre, to say characters are important to the story(Viola) & have them do nothing worthwhile, to make the protagonist an unlikable douche without someone else taking center stage at some point, to release an artbook spoiling what would be the rest of the story, to continue development through power outages and nuclear disasters...Yeah sure, you can disregard as much or as little as you want. But as long as you're grasping at straws to say it is or isn't rushed, more points towards it having been rushed than the opposite.