I think you’re missing the main context of the post, which is experience. It doesn’t matter if you were not an expert when you applied. What matters is that you are an expert when it is time to be, which includes the interview.
That said, common sense tells you that this is all about “additional skills” like specific softwares, not core technologies. If you’ve never heard about Java and you apply for a Senior Java Engineer position, you’re probably not going to do well.
I think you’re missing the main context of the post, which is experience. It doesn’t matter if you were not an expert when you applied. What matters is that you are an expert when it is time to be, which includes the interview.
That said, common sense tells you that this is all about “additional skills” like specific softwares, not core technologies. If you’ve never heard about Java and you apply for a Senior Java Engineer position, you’re probably not going to do well.