The way I see it even after Hypersonic missiles make their debut by 2025 or so they will not replace all the supersonic missiles.
For instance,
(1) Currently there are no Air to Surface missiles that are even Supersonic, so it is not possible that they may become hypersonic.
(2) Even Surface to Surface missiles barring Oniks/Brahmos is Supersonic.
So we are left with
(1) Surface to Air Missiles that are Supersonic - SM3, PAC 3, S-400, Arrow 3
(2) Air to Air missiles that are supersonic
(3) Re entry vehicles of IRBMs, ICBMs
Ergo, which missiles will be replaced by Hypersonic missiles ?
For instance,
(1) Currently there are no Air to Surface missiles that are even Supersonic, so it is not possible that they may become hypersonic.
(2) Even Surface to Surface missiles barring Oniks/Brahmos is Supersonic.
So we are left with
(1) Surface to Air Missiles that are Supersonic - SM3, PAC 3, S-400, Arrow 3
(2) Air to Air missiles that are supersonic
(3) Re entry vehicles of IRBMs, ICBMs
Ergo, which missiles will be replaced by Hypersonic missiles ?