And...those are two entirely different things.
Not particularly different. If anything, portable weapons would have a greater excuse for being put out of production when they grow outdated. But there is no motivation for ceasing the production of "primitive" revolvers, so there certainly shouldn't be a motivation for doing major changes for a "primitive" starship which is a much more complex industrial effort to begin with and would require much more effort to redesign. Not unless something about the threat environment changes - and nothing should change for a science vessel, as its "threats" have stayed constant for billions of years already.
could well be the revolver of the starship world, facing a stable threat environment, while the Akira
would be the assault rifle, always in the need of tinkering to meet the evolving opposition.
built to specifications acquired from battling the Borg
Only a single starship type is known to have been built to such specs - the Defiant
There might be huge disadvantages to making a ship "Borg-compatible". Such a vessel might be an inferior combatant in a fight against the Klingons, who do not
stand still behind a square target three kilometers on side, without conventional shields, just waiting to be boarded by transporter.