Yes, and it's about as close as a dupe ever gets. Dulux Mysterious Teal comes in at ΔE 0 from Dulux Heritage Midnight Teal — that's an imperceptible difference, so for all practical purposes you're looking at the same colour. It sits at LRV 9.5, deep and inky, exactly where the Heritage version lives.
This isn't surprising, mind. Both are Dulux products from the same parent stable, so the Heritage line and the standard line share a lot of colour DNA. The difference you're paying for with Midnight Teal is the Heritage formulation and finish quality, not a unique colour. If the budget's tight, Mysterious Teal gets you there.
If you fancy looking further afield, Crown Endeavour is a very close second at ΔE 2.9 (LRV 9.8) — a touch lighter and a hair off, but in a real room you'd struggle to call it. And COAT The Drink lands at ΔE 3.9 (LRV 7.4), slightly deeper and the furthest of the three, though COAT's eco-credentials and low-VOC formula win it fans if that matters to you.
The "but what about" here is finish. These deep teals live or die on the sheen. A dark colour in a flat matt can look dusty and flat in low light; in eggshell it picks up depth and richness. For walls I'd go matt or modern emulsion, but for woodwork and panelling — where teals like this really sing — get it in eggshell or satin.
One practical tip: at LRV under 10 this is a properly dark colour, so test it on a couple of walls and live with it for a few days. Deep teals shift hard between a north-facing room (cooler, more navy) and warm artificial light (greener, lusher). Order sample pots of Mysterious Teal and Midnight Teal both, paint them side by side, and you'll see for yourself there's nothing in it.