Do OT scriptures clearly indicate sacrifices will be replaced? The author of Hebrews builds the case that the substitutionary sacrifice of Jesus has replaced the OT system of animal sacrifices. Are there any OT scriptures that clearly indicate the Jewish system of sacrifices would eventually be replaced? There is the Jeremiah 31 passage quoted in Hebrews, but other than that the author doesn't seem to state, "This scripture says sacrifices will one day be replaced, and Jesus did that on the cross."
The writer to the Hebrews [Heb 1:1,2] makes it clear that the very repetition of the sacrifices, themselves, is proof of the fact that they are not effectual. And the only reason for their repetition could only be an intelligent expectation that something better would arise.

For the law […] can never with those sacrifices which they offered […] make the comers thereto perfect. For then would they not have ceased to be offered ? [KJV]
[…] because that the worshippers, once purged, should have had no more conscience of sins.
But in those [is] a remembrance again of sins every year.

As with any repetitive ritual, some will be content, thoughtlessly, to continue with a habit thinking that a mere performance will be effective spiritually. And it is clear that many of old were so contented with the outward representation - and looked no further.
But to the intelligent worshipper it was evident, in the very repetition, that this was but a means to an end, but an herald of a reality yet to be revealed.
Until that revelation, there could only be the representation. The prophets speak in many places, in many ways, of that which was promised. But I can only think of one definite prophecy that is relevant to this particular question, which is Daniel 9:27 :

[…] shall cause the sacrifice and oblation to cease,

but it is a mysterious prophecy and I would not wish to venture to say more about it.