I'm shutting this down.
1. The OP is currently in Aus, is not married, does not have a valid visa, and has no "urgent" need to return to Thailand per the Thai government regulations.
2. There are two types of retirement visas (basically): A Non-O and a Non-OA. AS OF RIGHT NOW, the Non-OA need health insurance, the Non-O visa does not need insurance. IF he wants an Non-OA visa, he can use
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to get a quote from an approved insurance company
3. AS OF RIGHT NOW, the consulates are not selling visas.
4. AS OF RIGHT NOW, to enter Thailand, COVID-19 health insurance is needed. The OP can not enter Thailand, and therefore will not need COVID-19 insurance. Will it be needed after the borders reopen? I don't know, my crystal ball is broken.
MY ADVICE:
The OP should continue watching the news, and when the borders reopen, to apply for a visa, insurance (if required), and to come to Thailand. We don't know what the future holds.
Good luck