In addition to what Ignacia Gully shares below, Commodore had plans to integrate some kind of network support (assumingly their TCP/IP stack [front | back] and Digital Signal Processor  support into the AmigaOS).
Amiga Report International summarized the following notes from the World of Amiga show in Pasadena, California on September 11, 1992 during The Future of the Amiga presentation given by Lewis Eggebrecht, VP of Engineering:
"However, at WOA Commodore said that they would ship more new products in the next six months than anyone could believe possible. This includes AmigaDOS 3.1 (with network extensions and DSP support), and Digital Signal Processor upgrade for the A4000. They also mentioned retargetable graphics and PostScript support in AmigaDOS 4.0..."
Lewis Eggebrecht reiterated Commodore's intentions for the DSP at the World of Commodore in Toronto, Candana in December 1992: "DSP on processor board, expect by late spring , details at the Orlando Developers' Conference in January."
The Amiga 4000T manual, on page 1-9 under the "Audio" chapter, "Audio Expansion" section, includes this paragraph [bold emphasis added]:
"If you install a CD-ROM drive or a DSP expansion board, you can connect the drive or board to the header on the audio/video module, illustrated in Figure 1-3, so that its audio output can be mixed with the Amiga's audio channels."
Contributor Ignacio Gully explains:
AmigaOS 3.1 was never supposed to have been released. It was Village Tronic GmbH, makers of the Picasso series of graphics cards, that released it for their customers as it contained a few fixes that were valuable for ReTargetable Graphics (RTG) card owners. Village Tronic was a registered developer of AmigaOS, as many other companies were, so they had early access to confidential ongoing development work, which included what we now know as OS 3.1.
Commodore sued them because of this, and ended the 3.1 distribution. But given their opportunistic nature, Commodore realized that it was a reasonable idea to release whatever sellable content they had for 3.1. So, it quickly became an official release, despite originally being an unintended one.
Before Commodore went bankrupt on April 29, 1994, the following updates to OS 3.1 were in development, but either never finished or released:
"Ultimately, the 68060's highest volume market will be as an embedded processor in equipment such as printers and communications equipment, Reinhart [Jim, Motorola's manager of 68000 marketing] said. Eventually, the chip will be targeted more toward that market, Motorola indicated, and will lose backward compatibility with its predecessors. "We won't be responsible for 68040 compatibility in future generations [of the chip]," Reinhart added."
All this development was what would have been version 42 of the AmigaOS, though with no specific number assigned to it. The work was far from complete and appears to be in an initial state; very much a work-in-progress development halted by bankruptcy.
Of course, later, by approximately 1996 some development work resumed under Escom/Viscorp and Amiga Technologies, but that is just another chapter of the Amiga story.