This is a good question, just like why she decided to go to the park at all in the first place, we do not know, and may never know. I could only guess she was going somewhere to meet someone to do something, and somehow she ended up in the park
So you could only guess that she was going somewhere else and ended up in the park somehow?
That is higher probability to you than her just simply going to the park to meet someone in the park and waiting for instance?
I have said before that I think there is a chance that another form of communication was used to redirect her to that park. Maybe using something like snapchat? a burner phone?
A burner phone is a prepaid cheap older model phone that is not connected to a specific person, that is used very often in drug dealing, where someone can communicate for a short period of time and then just destroy the phone. So if we were to just entertain the idea that this was a drug deal gone bad, the fact that there was no communication to be found as to why Toni was there, this aspect actually fits the profile of using a burner phone.
It's a very common practice in that world. But sure, people can choose to ignore that and how much sense it makes. But... it's still a thing and consistent with what we see here.
This case right here, is an exact example of why someone would use a burner phone. They might even do regular interaction with her on their smartphone BEFORE she went missing, calling her to another location, and then say she didn't show up. Giving them the ability to say they were somewhere else.
gee... hey, didn't that happen in this case?
Hell, possibly even left their smartphone at that location with someone fiddling with it to give an alibi. Would be interesting if that is the alibi right?
food for thought.