They do it with all requirements, make it very difficult for people to come. When you see requirements mentioned for restart of tourism, tourists will not come to Thailand.
I am not sure you are correct in saying you do not have to report coming back from abroad. As I read it, the landlord or house owner (for me my wife) does not have to report anymore.
That also is a huge benefit to some, as they do not have to chase their landlord to do the paperwork.
If they do not want to but do not have the right papers to stay here, Thailand will probably make them leave. I would not bet on being able to stay here only because you want to.😉
Why did you have to go out of Thailand to get Non-O based on marriage? I got mine in Thailand. Is it because you do not meet requirements when you apply for Non O inside Thailand?
People can not do a border run, but they have a place to go to: home. I am not saying this to be rude, but I believe this is how the amnesty will be interpreted.
He is here on a visa exemption, so in Thai eyes he is a tourist. Tourists can go home.
Probably they do nothing to make you leave, but you will be on overstay. So not everybody will have to leave at once, but those getting caught will probably have a problem.
I hope for people on tourist visa they get more time, but if amnesty ends 31 July, there is not much they can say. Immigration will say tourist had a lot of time leaving Thailand.
Just my thought on the situation, not claiming to be an expert.