The answer is no. An old rub indicates nothing more than a buck used be their, the only way to know whats their now is fresh sign, visuals or photos of the deer. I love hunting rublines & have taken a good number of bucks with them in the mix, but their has to be some elements present before I set up on a rubline: 1) fresh sign & right time of year(no point hunting a rubline in early bow when the bucks are grouped up) 2) be in transition areas and under cover 3) not directly in the bedding area 4) funnels, bottlenecks or similar land mass the sends deer my way 5) minimal pressure to the area (basically the deeper, nastier the better).

Like others said use it as a starting point but don' t relay on a rub or scrape to produce. The best place to get on top of bucks consistantly is transition areas. Place yourself between fresh sign such as rubs, scrapes, food or water and their bedroom. You want to make sure not to setup in the bedding area as pressure here and the big bucks will leave and not return. Never hunt these areas on a marginal wind. Change up your location to minimize the pressure you put on the deer.

I suggest you keep a log and have a map to plot findings such as rubs, scrapes, water, food, bed, trails, etc. This will help you visualize where you should place stands and hunt for any given situation and time in the season.