Truesight is defeated by Shadow of Moil that u…

Truesight is defeated by Shadow of Moil that use the heavily obscure effect, is this correct?

@JeremyECrawford Hi Jeremy, quick question about shadow of moil. It heavily obscures its caster with shadows. I take the shadows as flavour and understand that truesight is defeated by spells that use the heavily obscure effect, is this correct? — Thomas Mullins (@MythranKirel) December 19, 2017