Output drive and fan-out
The output is rated for 3mA high-level and 24mA low-level drive. That 24mA sink is typical for 74F — enough to drive a few standard TTL loads or a single LED indicator directly. If you are feeding a long backplane trace or a high-capacitance bus, you will want to buffer the output; the 3mA source side is the weaker link. The 24mA sink figure also tells you the output stage can absorb current from a pulled-up bus without exceeding the absolute maximum, which is the usual case when multiplexing onto a shared data line with passive pull-ups.
Lifecycle and sourcing
No last-time-buy notice, no obsolescence pressure on this line item. It is a current, standard-product multiplexer from TI that remains in the catalog for new designs and production replenishment alike.