My concern is not really that the part is old....It is more that "can you get in in sufficient quantity" for your production needs over the life of the product. I sometimes worry about that when a chip from the mid '80s proposed for a design.
Michael

P.S. If it is for a home or school project where you only need 1 or 2 parts it is not an issue at all (if you have them in your parts bin or can get them at the local electronics shop or steal them off some old circuit board).
MJK