As for external usage of the method - MediaTek is one of the largest chip design companies in the world, and they built on AlphaChip. There's a quote from a MediaTek SVP at the bottom of the GDM blog post:
"AlphaChip's groundbreaking AI approach revolutionizes a key phase of chip design. At MediaTek, we've been pioneering chip design's floorplanning and macro placement by extending this technique in combination with the industry's best practices. This paradigm shift not only enhances design efficiency, but also sets new benchmarks for effectiveness, propelling the industry towards future breakthroughs."
The more marketing claims we see, the less compelling the Google story is.
Your perseverance is as admirable as it is suspicious. You are the lonely voice here defending the Google announcement.
Even if the AlphaChip authors redid Kahng's study properly, this still wouldn't give us useful information -- what matters is AlphaChip's ability to optimize chips in a real-life, production setting, for modern chips, where millions of dollars are on the line.
Other commenters already addressed the pre-training issue. Please kindly include a link to Kahng's 2023 discussion addressing your complaints. Otherwise, you are unfairly supporting those people you know.
Kahng's placer is open-source and was used in the Nature paper. It does not make sense to accuse Kahng of colluding with companies against open-source.