It's possible that Royal Enfield may have made changes to their product offerings since then, which could include the discontinuation of certain models like the Thunderbird.
To obtain the most accurate and up-to-date information on the status of the Royal Enfield Thunderbird model, I recommend reaching out to Royal Enfield directly or visiting their official website or authorized dealerships. They will be able to provide you with the most current information regarding their product lineup and any potential changes or updates.