Media facilities used to build completely separate storage systems for IOPS intensive applications and Throughput applications. Is that no longer necessary? Can both these applications be served by a single storage system?

There still remains a difference. But I don’t think it is that important anymore in M & E in contrast to office database applications. With IOPS you talk about R/W of millions of small like 4kbyte files for example. With streaming kind of the opposite.
Of course the less latency the higher the IOPS but more important is the way how sharing (read/write locking) is done.
Systems optimized for IOPS use range locking to prevent unneccessary OS cache invalidations when small blocks are written. When are you telling the other users that this file has changed for example?. Those typical database applications are not common in M & E.
Audio files can be small but DDP is largely favored in this market. Video files are large so IOPS do not play a role there . Tiffs, exr, dpx are not small files either and the A/V FS metadata handling is largely optimized for these frame files.