I was thinking of expanding the current Trinket system with more ward types, and equivalent counters to each in exchange, while allowing every player to get one Warding and one Negating trinket.
Let's say we introduce mobile 'wards' that are equivalent to
's Ghosts, minus the slow, and/or an equivalent to a weaker version of the Wolve's smite effect in the jungle.
We can then open up a trinket that would disable all vision (without revealing them) from all wards in an area for several seconds to counter those mobile 'wards', and others.
As far as Pink Wards go, i'm not sure, but perhaps adding True Sight to the Ghosts instead might work, or maybe a Pink Trinket could allow its wearer to have more than one Pink, on a longer cooldown, since they'd likely be the only ones able to plant 'em. Either way, with this kind of system, there are infinite possibilities, we just need to think about them. Hell, even discounting the idea of mobile wards, we've got a lot of room to work with. Long range wards, larger line of sight wards...