If one believes that the Lord Christ only intercedes for His people per Romans 8:34 and Hebrews 7:25 then they must, if they desire to be consistent, believe that Christ only died for those same people for whom He intercedes. Both the death of Christ and the Intercession of Christ are subsets of His great work as our Great High Priest. To suggest that Christ died for everybody as the Great High Priest but only intercedes for the elect is to introduce contradiction into the very being of Christ as Mediator.
If Christ only prays for His people then He, by necessity, only died for His people.
Not to worry though … if you don’t agree you can always invent a Mystery Box in which to throw your contradiction.