Well, the overtone window certainly changed, but ... I judge a bit different here.

"expressing support for an alt-right ideologue"

This is what Kling actually said:

"RIP Charlie Kirk

I hope many more debate nerds carry on his quest to engage young people with words, not fists."

I also support fighting with words, not fists. I do not support his ideology at all and would have loved to debate him openly, but the concept of murdering someone for having the wrong opinion is disturbing to me, so I agree with Kling here.

And about "white replacement"

"'White males are actively discriminated against in tech.

It’s an open secret of Silicon Valley.'

One of the last meetings I attended before leaving Apple (in 2017) was management asking us to “keep the corporate diversity targets in mind” when interviewing potential new hires.

The phrasing was careful, but the implication was pretty clear.

I knew in my heart this wasn’t wholesome, but I was too scared to rock the boat at the time."

He said whites were discriminated for being white. Not replaced. That is not really the same to me.