▲是的，这里的come what may是让步状语从句: 它让人疑惑的是它的语序“不正常”。其实这样用的come what may已构成习语，如果要分析的话，可理解为：come what may=Whatever may happen=No matter what may happen。例句如：

He promised to support her come what may. 他答应不论发生什么事都支持她。

I shall be there tonight come what may. 无论发生甚么事，我今晚都会去。

It’s always good to know that, come what may, your job is safe. 不管怎样，你工作安全才是最好的消息。

My mother taught us to always tell the truth, come what may. 母亲告诉我们不管发生什么，一定要说实话。

I knew he’d be able to take care of himself, come what may.  不管发生了什么，我相信他能够照顾好自己的。

▲类似的倒装用法还有：

Say what you will, I won’t change my mind. 不管你怎么说，我都不会改变主意。

Try as I would, I could not persuade him to give up the idea. 尽管我努力这样做，我却没能劝说他放弃这个想法。

Strange though it may sound, I was pleased it was over. 尽管听起来也许很奇怪，但我很高兴这都结束了。