The reason is the refresh of the flagship Model S and Model X models.
Let's recall that the site launched in 2013 for final assembly, and in 2015 the company opened a new facility with an indoor test track.
Now, as Tesla is refreshing the Model S/Model X, the final assembly process will not be needed/possible:
"Tesla will stop "very shortly" with assembling the Model S and Model X in Tilburg. The models were upgraded at the end of January, which changed the production process in the United States so that assembly in the Netherlands is no longer possible. As a result, a maximum of 96 jobs are at risk, a source within Tesla confirms to NU.nl. Factory personnel were briefed earlier on Thursday." - via Google Translator
The first batch of new Model S/Model X is expected in the Netherlands in November. This alone means that there are no more cars for final assembly for about half a year.
Whether there will be some kind of new approach to final assembly later, maybe at some new site, we don't know yet.
The article says that more than 1,500 people work for Tesla in the country, including 540 in Tilburg, but only part of them on the final assembly line.
We guess that a company like Tesla, which expands in various directions simultaneously, can find a new purpose for its sites with ease. If the final assembly process is not needed at this stage, well, that's part of the business.
For Tesla, the most important thing in Europe right now is the Tesla Giga Berlin anyway.