I suspect some of the bulletins are only applied upon request or if it becomes a problem which makes sense just as
@HAWX 12 mentioned.
I can speak to this; I was previously on the team creating these documents. For Tesla specifically, look at the "classification" at the top of the document. If it's a "repair" bulletin, the Service Center will only perform it if the customer has a complaint that matches the symptom(s) listed on the bulletin. If it's a "campaign" bulletin, they will perform it on every affected vehicle the next time the vehicle is repaired by Tesla for any reason, assuming the vehicle is still covered by the relevant warranty. For a "recall", they will proactively notify the customer through an official letter, and repair it regardless of warranty status.
It is confusing because Tesla calls them service bulletins and NHTSA calls it manufacturer communications.
Some manufacturers call them tech notes, some call them service bulletins, some call them technical service bulletins, and different manufacturers separate these types of documents based on different criteria. So NHTSA just uses the most generic term.
They really need to go the extra mile and have companies include the entire list of affected VIN numbers so when you look your VIN up you also get a list of service bulletins that apply to you and not just recalls.
The manufacturers have only been required to provide this feature on their websites (for recalls) for a few years. For other bulletins, the dealer--or, in this case, Service Center--has this information. Early Tesla service bulletins (Roadster and early Model S days) actually listed every single VIN at the end of the document, which quickly became unsustainable. Even changing to VIN ranges was ugly, because they don't start at 1 and count up sequentially, so 20+ VIN ranges were shown in some cases.
After that, we changed to a date range in the "Affected VIN(s)" section at the bottom of the document specifically to help owners, 3rd party repairers, and technicians who didn't have immediate access to the VIN database--my idea was that someone could look at the approximate affected build dates shown there and immediately realize that the bulletin didn't apply to their vehicle that was built outside of that timeframe. It looks like this feature has been removed from newer documents for some reason.
I should also point out that it's likely that not every bulletin that affects your vehicle is on NHTSA's site, yet. The manufacturers send these documents to NHTSA regularly, but it takes them a while to process them and post them on their website. You can always see an up-to-date list on
Tesla's official service information site, but of course you'll need to pay for access to that site. Alternatively, check back on NHTSA's site from time to time to see what has been added.