No. Even if we ignore the people newly enabled to slop out vulnerable software without having a clue about security, the AI powered supply chain hacks inserting vulnerabilities, the influx of AI contributions that drown out improvements in FOSS security, and the industry pressure to ship faster while reducing quality or be left behind -- all because of AI -- security through obscurity has historically been the most effective security.
I don't think your argument holds under theory or (especially) practice.