A fast transition of this vein has worked before. Look at Thorpe Park, for instance; Tussauds threw everything and the kitchen sink at Thorpe Park during the 2000s to convert it from a family park into a thrill park, and that strategy really delivered the goods in terms of transitioning the park from family to thrill and growing its guest figures.
Between 2000 and 2007, park guest figures roughly doubled (in 2000, the park got ~937,500 guests, and in 2007, the park got ~1,843,750 guests; that’s an attendance boost of about 97%), and guests’ perception of Thorpe Park was changed pretty drastically. I’m aware that this bubble burst from about 2012 onwards, but I don’t think that it was the initial fast transition of the 2000s that caused that bubble burst to occur. Other factors played into that; the initial fast transition to thrill actually did very well for Thorpe Park, and had some degree of momentum continued into other areas, I think it could still have produced great results for them to this day.