In theory if you can completely saturate the 1 gbit link for a whole month it's 300TB/month
nice catch
Yeah, "unrestricted" is a better term here.
If something is not unlimited in theory, but it is unlimited in practice, then it is unlimited.
The amount of electricity on Earth is not unlimited so at the end of the day there is a literal limit to the amount of data that can be transferred but for the purposes of advertising the product it's fair to describe the bandwidth as unlimited since what we're trying to do is inform the customer so they can make a purchasing decision :)