Not quite accurate, and indeed quite inaccurate when it comes to interline itineraries.

A lot will depend on whether the plating carrier is the carrier on which you no show. If so, there is a strong chance that your itinerary will be cancelled as stated above.

If your no-show however is on a receiving carrier, what exactly will happen depends upon the level of connectivity between the IET partners and what kind of DCS parameters are in use at the departure airport. Without going into too much of technical detail, most no-shows in this case would be queued for manual review prior to cancelling downline segments - often giving you enough time to actually utilise the subsequent ticket coupons. Even if manually reviewed, if the fare components are not linked (constructed as "end-on-end" rather than "add-on") then your downline segments may not be cancelled at all.

Sound advice though is to not take the chance unless you are 100% sure of what you are doing.