First, I'm not here to debate the consistency of the in-consistence of PDBs. There have been times where we are so late (from scheduled departure), and catering hasn't even been around, where I can't provide PDBs...not even water or OJ. When you're late, it's best to just board and go, then serve everything in the air.

Yes, Pre-Departure Beverages should be completed each flight. However, there are circumstances that may restrict receiving them as well as some restrictions according to local liquor laws or location specific alcohol restrictions
There was a message from the VP of Flight Service, when PDBs came 'back', that if a rushed boarding or late catering and if time allows, try to attempt a PDB with Water, OJ to quench the thirst before departure. It was even mentioned that he understood that there are times it's just not possible.

American Flagship Service & International Premium Destinations (AFS & IPD)
First Class & Business Class
Water, OJ, or Sparkling wine

Should be picked-up prior to aircraft movement

Domestic First
Beverage of Choice

If late catering, quick turn-around aircraft, an abbreviate PDB is allowed if time available...which means, at least Water & OJ
Should be picked-up before aircraft movement, and on few aircraft can be before take-off (PDBs stop at door closure, and picked up before aircraft movement)

Restrictions:
Connecticut - Alcohol may not be served while the aircraft is on the ground
Texas - Alcohol my not be served while aircraft is on the ground 0001-1200 on Sundays, or Monday-Saturday 0001-0700. (ok, I may at times forget this last one...oops)

For Non-International Premium Destination (NIPD)
Canada, Caribbean, Mexico and all NIPD destination including Northern Rim Latin America

FC/BC alcohol/liquor/beverage carts may be opened once customer boarding has begun on both US outbound and inbound for the purpose of serving non-alcholic beverages only if needed. (I get many odd looks when I asked what non-alcoholic beverages they'd like before departure...many don't realize we're suppose to only serve non-alcoholic beverages)

IPD
All International Flights to/from the U.S.
Carts containing alcohol aren't opened prior to 10,000ft
Carts containing alcohol must remain sealed at all times while aircraft is on the ground in the US and in all International Premium Destinations

(Champagne is boarded seperately for the purpose of PDBs)

For me, I will do a PDB once majority of my FC/BC pax are on board. I'll take as many orders as I can, then deliver them when I can. I will try to get those who come late if I can, sometimes I do miss them.

I get nasty looks from pax (generally those who are sitting in FC/BC for the first time) when I take their PDB away and it's still full....as they don't realize PDBs must be taken and thrown away before aircraft movement.

There are also laws about serving on the ground too. We can't just serve while sitting.....waiting for push-back or take-off. Only the Captain has the authority to let us serve beverages on the ground. (usually during extended tarmac delays)

If you ever want to know what beverages we have, as long as there is an Entertainment Card in the seatback, you will find the list of beverages in there, including alcohol.