

Either he was arrested with no record of the arrest (i.e “disappeared”) which is a new line for the administration to cross, or he disappeared for another reason (by himself, or with help or coercion by a foreign entity like the CCP), and the FBI is investigating.
I hope journalists keep on this because the first option would be a huge problem that everyone needs to know about, but without more information, the second is also a possibility. The CCP is known to have agents in western countries that manipulate and pressure ex-pats to return to China. Keeping an open mind now will also strengthen the argument if evidence for the former comes to light.
I use sendgrid as my outgoing smtp relay to avoid ip reputation issues you mention. You still have to configure your dns settings for spf and dkim pointing at their servers instead of yours. Their free tier is 10x the email I’ll ever send so it doesn’t cost anything. There are a few companies in this space with free tiers. It works, but it isnt Gmail level deliverability. I still get spam binned occasionally.