Fire Charges become Dragon Fireballs when shot from Dispensers, and when it hits a block, it releases the particle effect and area of affect damage that the Dragon Fireball would. However, if a Fire Charge is held in the player's hand and a block is right clicked on, it does just start a fire as usual, nothing buggy there. I was expecting it to shoot a Fire Charge and light blocks on fire upon impact as they did previously, but I instead got the Dragon Fireball and it's effects as stated above. I was testing a Redstone setup I made where part of what it does is light Netherrack on fire from below using Fire Charges shot from Dispensers when I noticed this.

It's pretty simple to reproduce.
1) Fill a Dispenser with Fire Charges
2) Aim at a block to see the particle effect
3) Be in Survival Gamemode to experience Area of effect damage
4) Activate the Dispenser

The first two images show what I saw when I tested my contraption, an the last two images show me testing from a dispenser not aiming up and not at a block.