For anyone looking for the answer, actually for some reason even tho it IS indeed the hardhat local that is running the test in the background, .getDefaultProvider().getNetwork() shows "homestead" chainId 1, and getBalance of an address will show 0 eth...
ButSo in reality its still running the test with hardhat local.order to access provider when testing locally without a network specified, you should use ethers.provider.getBalance(xxx) and not ethers.getDefaultProvider().getBalance(xxx)