Yes to the basic question, he can have another career.
But success depends very much on things OP has not shared, like can they handle reconditioning and restarting the horse, including the jump training, themselves or will they need to pay for training and lessons? Do they board out ( if so does that barn take studs?) or does OP have a place with proper facilities at low cost? Is the horse serviceably sound for a jumping career or need expensive management to remain able?
Biggest thing, IMO and IME is OP needs to ride this horse a few times and see if he is going to accept the training and if he will stay sound enough in regular 4-5 days a week schooling to turn into a jumper. That goes double if not been in regular several days a week work for years getting only occasional low impact work.
Think those questions should be answered first before assuming its a good choice for this horse and OP.
Just sayin here but most times when horses sit mostly unused for years there’s reasons. They don’t keep them around and pay their bills but sell them on, especially in a professional competition operation that cant really afford to carry unusable horses if there js any hope they can be sold.
So, for OP, be careful. Trust but verify with neutral sources, no matter how much you want to believe everything you are told by a seller you assume has your best interests at heart when they are trying to get a long time unproductive horse off their books. Proceed with caution.