Yep got the same call/offer myself & just like you, am grandfathered w/TC+, as well as lifetime DVR. Since you know that once the promo runs out, you would NOT be able to go back to TC+ & would end up paying about $3 more for the same prog that is now the Choice+ tier.
Because of all this, I politely declined their offer - but I ended up getting another HD DVR upgrade for FREE & also got 3 months free of HBO, MAX, Showtime & HD xtra pak, so I actually ended up getting a better offer for my needs.