It was BS considering countless other games having no problem with sound. Decoding something like Opus takes ~30MHz of a single CPU core[1], meaning even an unreasonable situation of decoding 16 simultaneous uninterrupted 128Kbit Stereo streams would only eat half of one core.

[1] iPod Classic (1998 era ARM9) decodes 128 kbps stereo Opus at ~150% real time at stock cpu frequency. Opus is not the lightest choice either https://www.rockbox.org/wiki/CodecPerformanceComparison#ARM