Arguably...and arguably not.
On the one hand, master tapes degrade rapidly if not competently stored and handled (but much less with good preservation practices).
On the other hand, analog tape reproducer machines kept improving, and quite significantly. Experts in this area report that any music recording tape, new or old, yields higher quality audio when played on later reproducer machines. So if the DSOTM originals are well preserved, it can be argued that the later the remaster, the more detail is extracted from the tape. Hence, arguably, the original issue LPs are, compared to later remasters, limited by the quality of reproducer machine available in the day.