No clue where the interpretation comes from that this "neutrality" is extended to basically everything around the topic of war or military. Switzerland is a weapon export country and has been for a long long time. Neutrality for this only means they dont export to countries at war or if there is reason to believable that the recipient would sell it to countries at war or if it would fall in the hands of terrorists etc. etc.
The real swiss neutrality is way broader and includes mandatory independence. So while Switzerland can join sanctions they decide and do not agree in advance to join sanctions the EU defined. It also includes military mission to promote peace. Swisscoy is the association of the Swiss Armed Forces in Kosovo. This is not against the swiss neutrality because there is no armed conflict there. The Swiss Armed Forces there are still armed for self-defense only.