Which Mac models are afflicted with the "repeating keypress" issue?

Solution 1:

These models are affected as of 2019-07-16:

• MacBook (Retina, 12-­inch, Early 2015)
• MacBook (Retina, 12­-inch, Early 2016)
• MacBook (Retina, 12-­inch, 2017)
• MacBook Air (Retina, 13-inch, 2018)
• MacBook Air (Retina, 13-inch, 2019)
• MacBook Pro (13­-inch, 2016, Two Thunderbolt 3 Ports)
• MacBook Pro (13-­inch, 2017, Two Thunderbolt 3 Ports)
• MacBook Pro (13-inch, 2019, Two Thunderbolt 3 ports)
• MacBook Pro (13-­inch, 2016, Four Thunderbolt 3 Ports)
• MacBook Pro (13-­inch, 2017, Four Thunderbolt 3 Ports)
• MacBook Pro (15-­inch, 2016)
• MacBook Pro (15-­inch, 2017)
• MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)
• MacBook Pro (15-­inch, 2018)
• MacBook Pro (13-inch, 2019, Four Thunderbolt 3 Ports)
• MacBook Pro (15-­inch, 2019)

Source: https://support.apple.com/keyboard-service-program-for-mac-notebooks