I'd suggest that it's not that S&W has decided to refuse to sell the CHP configuration 4006TSW to the public for reasons of the features being restricted to LE, or that CA has any interest in whether it's sold to the public.
The CHP has decided that they desire certain features on their service pistol which wasn't part of the way it was normally produced and sold.
The recoil guide rod was different.
The wanted a spurless hammer. Not to be slick and neat, or because it was better, but mostly because they wanted to discourage their folks from trying to thumb cock the hammer and make a SA shot as their initial shot.
The spring-loaded, decock-only feature was originally designed and intended to be a LE option back in the middle 90's, granted. It doesn't allow for an ON-Safe manual safety, but it also makes sure the pistol is in a ready-to-fire condition ... meaning the user won't draw and present the pistol and try to fire it with the safety unknowingly on. Some folks might not believe the number of times that something like this can happen on a training and qualification range with folks who carry their pistols in the off-safe/ready-to-fire condition ... and they get distracted and forget to return the safety/decocking lever to the ready-to-fire position. Critical moments can be lost in the middle of an actual shooting situation before they realize their weapons are ON-Safe. Not good. It wasn't a standard feature on their commercial guns, or even the LE guns ... but it was available as an option. If a commercial customer wanted it S&W would install it on their gun, although only the TSW and the 4040PD slides routinely received the extra machining necessary to accept the option.
The lack of a trigger play spring would probably annoy some segment of the commercial market, since it results in some increased play and slop in the single action trigger ... which isn't something really noticed by most LE users, though. I've never had a LE user able to tell me that they had noticed the increased looseness of their trigger when I discovered their trigger play spring was missing. Nor did I really notice the lack of one in one of my guns during an extended 800+ round training session over the course of a couple of days. Too busy running through different courses of fire. Private owners tend to take more notice of some things, though. You can read various postings of commercial owners who want to know what the 'click' in their SA trigger stroke is, or how they feel their SA trigger has some extra movement before it breaks.
The adoption of the accessory rail into the frame was a long overdue idea, though. I've never particularly cared for the bolt-on appearance. Even seen one break off and have to be replaced.
The problem with the integral frame rail feature is one of timing, though. The cost of producing the metal-framed TSW series is such that the price is significantly higher than a lot of S&W's other pistols. If commercial sales won't support the production, they aren't going to be produced for commercial sales.
Now, maybe some increased demand from the non-LE market will result in S&W deciding to make limited production runs of the TSW series again. They're certainly good guns. I'm one of the folks who sincerely feels the TSW models can stand should-to-shoulder with any other expensive metal-framed pistol of similar cost and hold their own.
Although I'm not really a user of pistol-mounted lights myself, I wouldn't mind seeing the integral rail concept applied to the 4513TSW, 4013TSW and even the 3913TSW.
Then again, I keep waiting for them to decide to make an all-steel version of the 3913TSW, which we could call a 3916TSW.
FWIW, when I was asking someone at S&W about the potential of having one of the big distributors order a production run of some TSW's, I was told that they'd gladly make them if they're ordered. Folks should probably expect to pay a pretty penny for them, though, at least compared to less-expensive-to-produce models.