The mothers are of a recent enough vintage that they had ghosted on dates, so why would they think any differently about a get-together for their kids' classmates?
This incident happened in 2018, so the kids in question were born in 2011-2012. It's safe to say the mothers were actively dating between 2005-2010. Additionally, I'm sure there were some single moms in that group who were dating in 2018 too.
The married moms who dated between 2005-2010 were on the forefront of the ghosting pandemic if they were using websites like OkCupid, PlentyofFish, and Match to date in those years.
Ghosting and flaking exploded after the iPhone was introduced in Summer 2007. In 2007, I was 24 and I had been actively dating for 8 years at that point. Prior to Summer 2007, I don't recall a lot of ghosting. In the era from 2001 (when I turned 18) until Summer 2007, I remember the greater challenge was getting someone to agree to a date. Once I got the date agreement, I don't remember dealing with ghosting and/or flaking.
It was more difficult to ghost/flake between 2001-Summer 2007 due to limitations in communication modes back then.
Women had to pick up a telephone and call a phone number (either a landline or a pre-smartphone cell phone) and cancel. They might actually have had to have a voice conversation. If women wanted to ghost or flake via phone then, a common tactic they'd use is to try to call at a time when they thought you wouldn't answer the phone and leave a voicemail.
In the youngest segments between 2001-Summer 2007, AOL Instant Messanger was popular and was essentially a precursor to texting. However, the person had to be online/have an automated away message up for a ghosting/flaking via AOL Instant Messanger to occur. I just did a quick Google search and found out that AOL Instant Messanger didn't allow messaging to offline members until 2006. This wasn't a realistic option a lot of the time and certainly not as much as the next option I'll detail.
Around 2003-2007, texting started to catch on with the youngest people (I was 20-24) but texting on flip phones was a pain. There were some cell phones with slide out keyboards that made texting easier and those starting coming up more around 2005-2007, but texting didn't really take off 2007 with the first iPhone and the late 2000s craze around Blackberries. Even between 2003-2007, I don't remember receiving a lot text messages and I don't remember receiving flaking notifications via text until after the first iPhone came out. Between 2003-2007, the real exciting point of cell phone was being able to call someone on the phone wherever they were instead of hoping that someone was home to catch them on a phone call.
The only other communication mode for flaking back then was email. Emails were rarely used for flaking but they could be. I don't recall ever receiving a flake by email in those years. Now, email is a joke. Email is mainly a business communication tool, marketing method for brands (including newsletter deliveries), or mode of communication for Millennials/Gen Z to send long form messages to their Gen X/Boomer parents. Very few people give a shiit about email now and it's mostly useless in dating endeavors.