If you summon a bee with "/summon minecraft:bee ~ ~ ~ {Silent:1b}" it will still produces sounds (the subtitles show it, too). This will also work with "/data merge entity @e[limit=1,tag=test-sound] {Silent:1b}".
If you summon a bee with "/summon minecraft:bee ~ ~ ~ {Silent:1b}" it will still produces sounds (the subtitles show it, too). This will also work with "/data merge entity @e[limit=1,tag=test-sound] {Silent:1b}".
Confirmed 20w06a