Hi gefen,
I am going to throw in my two cents, which these day is worth -.47 cents, so I may owe you some money in the process.
I have nothing against implied concepts and meanings to words which are understood ‘not’ by exact, traditional definition. After all, except for one language, the traditional definitions had their formative stages and cultural influences.
This case bothers me too. The action verb, “went” implies the added concept of going with some degree of willingness or a level of agreeability or cooperation.
The linking verb “is” merely states a condition of being without the added footnotes. Even though going somewhere often requires the use of feet, the footnotes of willingness, on one’s own initiative, etc., are not there.
If the linking verb “is” is available, I think it would be a better choice.
On the other hand, the more I think about this, the more perspectives I get. So, I will leave it at that….
Also, you may want to consider your feelings on, “He just up and went missing.”