Re: Shrink for Azure SQL Database Hyperscale is now generally available

It is mentioned in the linked document in this article.
Index maintenance after shrink

After a shrink operation is completed against data files, indexes might become fragmented. This reduces their performance optimization effectiveness for certain workloads, such as queries using large scans. If performance degradation occurs after the shrink operation is complete, consider index maintenance to rebuild indexes. Keep in mind that index rebuilds require free space in the database, and hence might cause the allocated space to increase, counteracting the effect of shrink.