I understand the concern, but frankly, they probably won’t add this until they officially offer sales and support to other countries. There are a lot of challenges (including added costs) related to supporting different countries. Many products that DO support multiple countries sell a different version of the product for that country. Wyze currently only comes in a US version. (The included plugs, for example, are ONLY the North American type.)
I get that people from other countries are technically able to get their hands on the product through unofficial channels, but Wyze doesn’t recommend this, nor is it something they can really control. (The non-US Amazon storefronts are not considered official resellers.) The only thing they could really do to curb this would be to block foreign IP addresses, but that would effectively brick the product for any existing international users, so I doubt you’d prefer that.
In the meantime, if you’d like to use 2-factor authentication, you might try signing up for an US-based number with Google Voice or some other VOIP provider. You can also vote for these wishlist items related to international support. It’s certainly on their radar, but they’ve already said it will be a little further down the road.