I think this revaluation is not just for Mayura/ Ashva, but all IDFC cards in general. The T&Cs indicate that this multiplier towards hotel and flight bookings, is applicable to all credit cards from IDFC, and not Mayura and Ashva alone. Following is the multiplier factor for IDFC's LTF CCs -
Flight Spends: LTF Cards (FIRST Classic, FIRST Select, FIRST Millennia, First FAMILY, First Wealth) = 20x Bonus Points/ 150 Spent
Hotel Spends: LTF Cards (FIRST Classic, FIRST Select, FIRST Millennia, First FAMILY, First Wealth) = 50x Bonus Points/ 150 Spent
Point Conversion 1 RP = INR 0.25
(Similar is the case for LIC Cards, Power Cards etc.)
IMHO, While Mayura 2.0 has a higher Point conversion at 1 RP = INR 0.5, and 30X bonus point multiplier for flights, I think other IDFC CCs have become powerful too. So, if someone has a decent primary card (say Atlas), and a free card IDFC card (say select or wealth) then the travel/ hotel rewards of the free IDFC card along with, the 5999 + GST fee saved, will prove the upgradation to Mayura/ Ashva unnecessary. If, however, someone does not have any 0 Forex card with decent rewards, then the Mayura/ Ashva no more remain as bad as they were earlier, and maybe considered.
I think all IDFC cards have now become an excellent back-up choice for Atlas, once the travel spend ceiling of 2L/ month is reached.