Katie,
Thanks for your question to planDisney!
Character greetings did change a few years ago to accommodate the need for social distancing. As time has moved forward, the way we can interact with characters has changed closer and closer to the original way of meeting our heroes, though it has not quite made it all the way back.
Right now, select characters are available at what are called "character sightings", where you can pose and chat with them, separated by a rope line, to your heart's content. There have been some comments from Disney executives that as health conditions continue to improve the older format of character greetings may even return, though there is no date set for that at this time. Finally, with the arrival of the Disney Genie+ service, a number of these greet opportunities have been added as a selection for reserved times.
Some of the more popular greet events include
These are not the only ones, so check on your
My Disney Experience App to see who is greeting guests in your park, including where and when.
As for pin trading, it is still a very active pastime for many fans. Last spring break one of my daughters enjoyed exchanging pins with a cast member at
EPCOT. This site is located at the Camera Center in EPCOT most of the day, under the shadow of
Spaceship Earth.
Write me back if you have any other questions.
Have a Magical Vacation!
Doug