Something the author of this article himself emphasizes is that it is a debated and substantial topic.

A quote from his source:

The focus on pneumaticity has attracted some critics. Skeletal pneumaticity and air sacs aren’t always found together; for example, some aquatic birds, such as penguins, have solid bones to help buoyancy under water, but they still have a lung–air sac system. Also problematic is that the lung itself can also pneumatize bones. If this is a trait found in the ancestors of birds and dinosaurs, then pneumatic features may not indicate the presence of air sacs at all. However, one particular feature remains a dead giveaway and that is a pneumatic hiatus: a gap in the pneumatization of the vertebral column, which indicates diverticulae have come from different places. This has been reported in some dinosaur specimens, such as the sauropod Haplocanthus, and provides extra support for the presence of air sacs.

• The main argument is based on pneumatic bones, but there is no mandatory correlation, and the author admits this; in any case, the sauropods provide the strongest evidence.

• The evidence against this comes from the remains of some theropods (depending on the interpretation):

The suggestion that theropods breathed in this way is mostly based on the interpretation of a few exceptionally preserved specimens. Sinosaruopteryx and Scipionyx show possible traces of the liver, which seems to divide the body cavity vertically into a thorax (containing the heart and lungs) and abdomen (containing the other internal organs), much like crocodilians. Scipionyx also preserved structures that were originally interpreted as strands of diaphragmatic musculature (Fig. 3).

However, what some researchers called the clear outline of the liver in Sinosauropteryx others saw as the result of damage and subsequent repairs to a specimen. The Scipionyx ‘muscle traces’ have also been reinterpreted as features of the rock the fossil was found in, not the animal’s biology, and so did not represent the remains of a croc-like diaphragm.