Not in the way you think, though the manufacturer is being somewhat misleading.
Typically LoRa chips have distinct RF ports for a low band and a high band. But common LoRaWAN usage including TTN is on two different high bands depends on region; there isn’t a ready way for typical hardware to support that.
Not only is that manufacturer being a bit misleading, they aren’t even telling you which high band what you buy will have its high band networks tuned for.
It’s best to avoid buying from suppliers who give such hints that they don’t know what they are talking about.
Realistically speaking, long before you worry about roaming between different TTN band plans, you should worry about the fact that there’s only typically gateway coverage being donated in select populated (typically urban, or else simply unique in having an enthusiast) locations.
If you truly need global operation, you probably want something that uses a satellite uplink.