Not quite, as I mention elsewhere they continued incompatible low end systems, most prominently the existing business 1401 series, and used 360 technology to make the affordable 1965 1130. I would assume the same for the 1969 System 3, which eventually evolved in the AS/400 or IBM I as they call it now, which internally is still by far the most sophisticated mass manufactured computer system architecture.
I have to note that the AS/400 was so much ahead of its time it's still, in many aspects, ahead of our time.
https://spectrum.ieee.org/building-the-system360-mainframe-n...
"The company spent US $5 billion (about $40 billion today) to develop the System/360, which at the time was more than IBM made in a year, and it would eventually hire more than 70,000 new workers. Every IBMer believed that failure meant the death of IBM."
I think Honeywell started making clones of the old maschines and were successful and then IBM made that code run on 360.