Sisko wore three uniforms over the course of ds9, I think since he started the pilot wearing the tng style uni then they changed to the first contact uniforms. Picard also picked up a special jacket later on in TNG
I wonder if they ginned these up for Section 31 or Starfleet Academy (if that’s still a thing?) and figured they could use them here, similar to the First Contact uniforms being ported over to DS9.