Not at the point in the game he's referring to.

You only get fast travel at around halfway through the game. Which yeah, you can go to this area after you've reached this point in the game, but for most playthroughs, it doesn't make sense to play the game in such an order.

After beating the boss he's describing, to get back to Firelink Shrine is a significant hassle. And it's filled with a lot of annoying enemies, no matter which path you decide to take.

You might say a workaround is to rest at Firelink bonfire and refuse to stop at any other bonfires on the way there. If you realize you need to back-track, then use a homeward bone. But then, if you die, you do even more travelling than you would have had to do originally, like 4x the travelling if you want to get your souls and humanity back. Not exactly the most efficient option.

The mistake I commonly make in this area is forgetting to get the pyromancy glove after rescuing the pyromancer. I finally make it to the Wall Parasite and pick up Power Within, only to realize I don't have the glove. My playstyle usually relies on power within as a boss-killer, along with buffs. And Queelag is the first boss in the game that has a huge jump in health compared to all the bosses prior (Let's Player vegeta311 wasn't even sure if it was possible to include Queelag in his one-shot boss challenge because of this).

It can be a headache sometimes. More experienced players usually get through this area without forgetting to bring along the essential gear, but for someone who is on their first, or one of their first, playthroughs, it can cause a significant amount of anxiety.