Beethoven was horrified, then, when Napoleon declared himself emperor, a move that he feared would limit individual rights and lead to tyranny.

대략 의미는 이해가 잘 되었는데요.

Beethoven was horrified

A move would limit individual rights and lead to tyranny.

이 두 문장이 접속사 없이 쉼표로만 쭉 이어져 있어서 가능한 건지 질문드립니다.

when에 속한 부사절로 봐야하나요?