Deadlock is still in its early stages, which is why Valve has been dishing out so many minor updates. We've briefly seen new heroes and ways to traverse the map, whether that be climbing ropes or wall riding, and now there are also changes to the devious pause button.
Not long after Deadlock was officially announced and went into a closed beta trial, players figured out that not only was there a pause button, they could use it for evil. I've seen players pausing the match mid-fight just to trash-talk the team they were about to wipe the floor with, and one streamer even used it to get some recreational gambling in.
Initially, players could pause a game however many times they wanted, and while most people didn't exploit this feature, there were a couple of matches that felt like a slideshow because someone kept pausing. You can see just how bad it can be in a video that one player uploaded to Deadlock's Reddit—players can barely get out of spawn.
Although, as another player does point out in the thread below, repeated pausing was seen as a serious offence: "People are getting perma banned for this, so just report them, and hopefully the population of people wanting to mess up the game for others will dwindle."
Luckily, this issue has been addressed in one of the recent patches, sort of. In an update that happened late last week, the issue of pausing was briefly mentioned by one of the Valve developers in charge of Deadlock's patches. Now, players can only pause one time per game, a team can only pause three times maximum, and the game application will flash when the game is unpaused. It's not much, but it'll at least help prevent games being repeatedly stopped by players who want to cause chaos.
I'd personally rather there be no pause button at all, as even when it's used minimally, it can still be quite frustrating—especially when the match is about to end. However, it can be helpful if a teammate randomly disconnects, as it'll buy them at least 30 seconds to try and fix their connection and re-enter the match, and it's a nice feature for competitive play, or those almost-unheard of moments where you do actually have an emergency and are playing with 11 nice people.