Was hoping someone would do the math but what would happen is the convergence of rareness for 5-card hands. If the value of a hand is based on its improbability (which is not always the case), then the values of 5-card hands also converges.
The way i look at it is outs. In particular, hands which block their own outs increase in probability, while hands that don't, decrease in probability. For eg, a pocket pair is now 33% more likely than before, because after drawing your first card, you have 4 outs to make a pair, instead of 3. You are twice as likely to flop a set (4 outs instead of 2), and twice as likely to hit a boat/quads by the river. Hence, the value of boats/quads is significantly lower.
For a flush, its somewhat similar, but the difference in outs is less significant. For eg, a flush draw is now drawing to 13 outs instead of 9. Not double the probability like the previous scenario, but still about 45% more likely.
For a straight, the reverse is true. Straights dont block their own outs, so a OESD would still have 8 outs. Since you are now drawing from a 52 card deck instead of 47/48 card deck for turn/river, your odds actually decrease. Thus, the value of a straight should increase.
You also have to have extended rules for new hands, i.e. 5 of a kind, exact pairs, 5 of a kind flush?. Also, a royal flush is almost equally unlikely (kinda disagree with jackhammer that its way harder).