Hey @karthikb351,
It’s highly unlikely that the battery capacity has dropped. This has more to do with the predicated range of the vehicle based on your riding pattern.
Would recommend you check out the Ownership experience thread where this has been discussed in quite detail.
Helpful posts:
Post 1
Post 2
Post 3
Post 4
Post 5
Post 6
Do get back to me if you still need more clarity on this after reading these 
Regards,
Shreyas