Hi Kbfiredog,
Welcome to the Heartland Owners Forum.
Model years typically change in the spring, so 2021 Big Country builds have probably all been 2021 models for the past 5-6 months.
It's not unusual for Heartland to make some mid-model-year changes in Sept/Oct, so there could be a few puts/takes from what you've seen. It's all part of attempting continuous improvement and maintaining competitiveness.
If you want to find out what may have changed since the spring, you could call Heartland Customer Service at 877-262-8032 / 574-262-8030. Ask for Big Country sales.