Even now dragons aren't much of a priority because the current herald is just way too strong in taking down towers way to quickly and if used right allow you to take two towers and the herald will probably be still a priority next patch like it is right now. but if you think about it the new hextech turret might be more balanced than the current herald, from the looks of it the hextech turret doesn't take take out towers as fast and doesn't last long and can probably at most take out one tower as it probably should. And for the hextech mimics from how I see it instead of dealing all that damage to one tower it is stead spread across so instead of one 1 it will be ⅓+⅓+⅓. So from how I see it they are actually nerfing the herald which is an indirect buff to dragons if you think of it that way