You have the timeline all messed up.

Excel and Word both ran on Windows 2.0 (released Dec 1987). I supported Excel on Windows 2 in production.

In the late 1980s, yes, Microsoft and IBM told the industry that OS/2 was the future, because they both thought it was.

OS/2 1.0 was released the same month as Win 2.0) had no GUI, because it wasn't ready.

OS/2 1.1 had in, released nearly a year later in Nov '88. This was what Lotus and others needed. 1.1 was not good and barely worked. For example, OS/2 1.1 still had the Windows 2 MS-DOS executive style user interface.

OS/2 1.2 was nearly another year: Oct '89.

Now, it worked, it included advanced features such as the HPFS filesystem, meaning long filename support, it had a revamped and improved user interface, and the performance was OK... but also the 80386 had been out for 2 years and 386 PCs were becoming mainstream. OS/2 1.X was limited to the 286. That meant a maximum of 16 MB of RAM, that meant no ability to multitask DOS applications, and other serious limitations. The high end PC market was visibly accelerating away from the new operating system.

It also had formidable hardware requirements. For example it wanted 8 MB of RAM minimum.

Somewhere around the timeframe of OS/2 1.1 or OS/2 1.2 is when Microsoft realised that this project was running late, it had high hardware requirements, and yet it still couldn't fully exploit the hardware of new PCs shipping in the late 1980s, and it was becoming apparent that the future was not OS/2 after all.

So it's somewhere around the 1988 to 1989 that Microsoft realised that's unless it was willing to sacrifice the PC operating system market, it needed a fallback plan, it needed some kind of alternative: something that could run on high-end mainstream commodity PCs, which means a 386 with 2 to 4 MB of RAM, that offers more compatibility with DOS, DOS device drivers, and DOS applications than OS/2.

That's roughly the time that the school choir project within Microsoft started to turn into Windows 3. Windows 3.0 was released in 1990, it had the new user interface from OS/2 1.2, it could support and use the new facilities of 386 chips… but it could also run in just 1 MB RAM, ran quite well in standard mode in 2 MB of RAM, and ran really well with 4 MB of RAM in 386 enhanced mode with multitasking of DOS applications. In other words, in half the RAM requirement of OS/2 1.2, they could actually do more than that operating system could do, in terms of important things that MS-DOS users actually wanted and needed.

So yes in the very late 1980s, Microsoft did lie to large software vendors, promising them that OS/2 was the future, while it was working on something that would ultimately destroy OS/2. But even now I am no admirer of Microsoft, I have to admit that it was very far from a certainty that Windows 3 was going to be a hit. In the time frame that Microsoft was developing Windows 3, Word for Windows and Excel were already shipping products.

Yes Lotus and WordPerfect believed the lies. Yes it's true, Lotus and WordPerfect could've targeted Windows 2, but Windows 2 was pretty terrible and was a commercial flop. So if they had targeted Windows 2 it would cost a lot of money and the products would never have made it back. Yes they made a mistake, and yes later on Microsoft encouraged them to continue investing in that mistake, knowing that there was a gamble that might make it all a huge waste of money. But what they did probably looked like the sensible prudent decision the time.

And more to the point, relevant to your comment, this all occurred in the late 1980s, long before the industry went 32-bit and long before anybody even dreamed of Windows 4 which would eventually become Windows 95. That stuff happened in the 1990s, when frankly the OS/2 war was already long over.