These escort site ad reviews are mentioned in the article as being the exception in terms of erotic content. Regardless of sexual explicitness though, all the men appear to be of legal age. How are you concluding 'child pornography and solicitation thereof'?

It is possible that Google or some governmental entity believed that one of the many naked "18 year olds" was not actually 18 when the posted photos were taken. The comments on the linked post suggest that at least one reader of the blog believed that at least one escort was not 18.

That seems like adequate evidence for scrutiny, and it is possible that Google plays it safe in cases like these (I have no idea what their official policy is).

Something somewhere went horrible wrong when simply deleting a person's artistic life is how you play it safe.

Indeed - as anyone hosting pornography knows, it's generally on the people who took the photo, the people who uploaded it, and the people who are hosting it to have proof that their models are over age. If it turns out they're not, there's a risk of everyone who handled the photo being complicit in distribution of child pornography.

Why isn't offering escort ads by itself sufficient reason to immediately shut down his blog?

Since when do companies have an obligation to offer a platform for engaging in illegal activity?

I was wondering for a few minutes trying to find out what you mean, until I realized in the US that is illegal.

An interesting issue, what if the author of the blog would be from a country where it's legal - what right should, for example, a social media platform have to limit their speech?

(Especially in an age where some social media platforms are without alternative)

I googled and found that escort ads are not illegal - not unless they include sex. Which is obviously pretty easy to work around by simply not mentioning sex, but even so: escort ads themselves are not illegal in the US.

Escort ads are "illegal activity"? Where? In Simbabwe?