Generally not. Suggestions yes, actual training no. In today's market the managing broker recruits and solves agent problems. Most new agents need to join a team or get a mentor to learn the ropes.  

Your statement appears to be inaccurate and somewhat presumptuous- I presume to provoke counterpoints. So here you go:
Many brokers typically do not offer mentorship unless it is specifically requested, and even in those cases, the responsibility may be delegated to others. As a result, numerous brokers may lack sufficient support and training for new agents. The presence of an assigned mentor who genuinely guides an inexperienced agent can make a significant difference. The challenges often arise when such mentorship is absent, leading to situations where we inadvertently find ourselves having to babysit them on "in escrow" matters that should ideally be managed by a mentor from their brokerage.

As a new agent, I received "training" but it wasn't very helpful. The most useful things I learned by watching others and asking people not in my company. If a new agent could shadow an excellent agent, or agents, that would be the most helpful.

Q#1: Disagree. Not every brand-new agent has a broker guiding their every move.

Q#2: I agree that some level of guidance is necessary yet all managing brokers provide it which is a testament to the industry. 

Red Flags could fill a book. 

My brokerage office does a good job with guiding new agents, Andrew. But it's been 33 years since I was a new agent and I just can't speak to what others do. Most likely, as with many things in life, some brokerages do a good job and some don't.

I can only speak to my market and my own experience Andrew Mooers | 207.532.6573 and I have to say a DB that does a good job mentoring is a rarity.

NO, and that has been a problem for a couple of decades now. I know a couple of brokers who are nicely hands-on but they are in the minority. With the advent of 100% offices and some brokerages who get your desk fees and offer paid training but are not up in your grill making sure your paperwork is clean or listening to how you handle intake, many are 'raised by wolves' and I've seen some bad actors with brokers who are worse or AWOL. 
The brightest red flag is that their fat mouth writes checks their dumb ass can't cash . . . they come on like bombastic tweakers who can't answer questions but just try to force feed things through 'their way' thinking that's good negotiation strategy. They also don't know how to control their client and think they are being a 'hero' . . . 
We make deals gently, with honesty. We won't be threatened, lied to or powered-over. And we will help the new agent even if their broker did not help them whatsoever. To a point.
After which FAFO applies.  

At some firms yes, generally the best mentor programs are at smaller firms.  

It's always important to have strong DB support and in my market, I see it for the most part.  There are certainly some brokers I have worked with who weren't very good at all, haha.

I have had a cooping agent on a few of my listings, and never knew if their broker was watching closely.  Some needed more help.

All of our agents have great support.

We do run across inexperienced people from time to time, always try to help them.  Those who accept help get better, others who are too stubborn to accept help generally do not last.

Well that depends on the brokerage.  There are some good ones in the PHX area that offer a lot of training, mentoring and classes.  And there are some less than stellar ones that agents are on their own.  When I was the broker/owner you can bet we had vigorous training, sales meetings, as well as CE courses for the agents and others that wanted to come to the class.

What if i saw trouble......Double down and get them inline and going in a positive direction. Started with a talk in my office. And there were a couple that didn't make it and I sure didn't want the liability risk on my watch.

Sadly, it varies by office and DB.  Some are great, I had a meeting with two offices yesterday for my association and both of them have excellent DB support and dedicated trainers.  I've heard the opposite from agents at other companies.

Right....

Most new agents that I've worked with do not have enough broker direction nor instruction. I'm glad that I had it.