Confused with the TUP - M slot system

TUP - M

Ask ko lang po sa 3rd and 4th batch passers of TUPSTAT if guarantee po ba ang slots ng mga nakapasa for the 5th batch? If not, then why would even push a 5th batch to happen? Doesn't waitlist mean they didn't pass and/or almost passed? It doesn't look good if the 5th batch passers share the leftover slots of the waitlisted.