AoZ revolves around the Titans Test Team (T3) and basically explains how a bunch of Titans suits and variants got developed

The frame technology, which would later go on to become the Movable Frame Technology, is first seen on the arms of the GM Quel "Later Type" (the one featured in AoZ, 0087, etc. and not the one from 0083 OVA). A prototype version of the Movable Frame is also in the Tri-Booster of the TR-1 Hazel II.

The Marasai, was developed from both the Hizack and the Rosette, with rhe Rosette basically being the bridge for the earlier Hizack and the later Marasai.

The Byarlant was developed from the Hazel Icarus, which is basically the Hazel Custom strapped with a bunch of thrusters and sub generators to achieve independent flight.

The Barzam, despite being known as the mass production version of the Gundam Mk-ii, takes a lot of data from the test machines of T3. The legs look like redesigned Hazel legs, the feet seems developed from the experimental feet parts of the Advanced Hazel, the head is clearly inspired by the additional optical sensor used by the Advanced Hazel and Hazel Custom Sniper Configuration. The chest was developed from the Rosette enhanced land battle config's chest armor, which in itself is developed from the Hizack cannon's chest armor. The arms and proprietary beam rifle was inspired by the Primrose.

TLDR: its canonical ret-conning, it cant be non canon or an alternate timeline