I had the same doubts and asked for a mail explaining the scheme. This is what I got just 10 min back:
This is a Limited New Year OfferThis special offer is being made available only to some of our loyal customers so that we can provide better value for your money by providing maximum possible services at zero cost and to enable you to explore the full potential of Airtel Broadband.
If you are interested in availing this offer, I request you to kindly reply to this mail as soon as possible so that we can go ahead with the further process and provide you speedy service. A prompt reply will be appreciated since this is a limited period offer.
after 6 month your internet speed increases 2 mbps 24 hour.
We at Airtel are committed to offer our customers best in class services. I would like to thank you for believing in the brand and taking our services. Please feel free to call us at 121/ 44444121 (toll free) or mail us at
wecare.west@airtel.in for further queries/concerns.
Fair uses policy applicable all plan with this plan get the 1 mbps speed 100GB after that speed will be 512 kbps.
Looking forward to an early response.
PS: It seams that the plan name is still Freedom 1699, but customer segment is called streamer.
Other changes are A2A 1p/sec and others 1.2p/sec