Some teams have slogans, others don't. For a while in the last decade, the Mets were really guilty of some bad slogans, that are laughable now (The New Mets, Next Year is Now, or my personal favorite from 2003 – Catch the Energy). Here's a list of teams that slogans this season: (It's worth noting that some teams have repeated slogans from previous years, forming some identity. The Orioles and Cubs are examples of this).
Baltimore Orioles – This is Bird Land
Boston Red Sox – We Won't Rest
Toronto Blue Jays – Heart + Hustle 2.0
Minnesota Twins – This Is Twins Territory
Chicago White Sox – All In.
Detroit Tigers – Who's Your Tiger?
Kansas City Royals – Major League Moments
Oakland Athletics – Green Collar Baseball
Texas Rangers – My Texas. My Rangers.
Chicago Cubs – It's A Way Of Life
Florida Marlins – Catch Our Moves
Cincinnati Reds – This Is Reds Country
Houston Astros – We Are Your Astros
Pittsburgh Pirates – Pride. Passion. Pittsburgh Pirates
St. Louis Cardinals – We Are Cardinals Nation
San Francisco Giants – Together We're Giant
Los Angels Dodgers – It's Time For Dodger Baseball
First off, congrats to the Mets who at least don't have one posted on the top of the website, which is where I got these from. I like seasons without them. There are three teams talking about location, like territory or nation. So some of these slogans are essentially copies of each other. Some are creative like the Oakland Athletics and then others are just funny like the Marlins and the Royals.