The quick impression I have from reading through the first two pages of this thread is that people have no idea what meditation is, or at least the kind the Dalai Lama means. The word 'meditation' here seems to be used as an umbrella term for all types, even prayer, when in practice that is not often true. Most people pray for ceremony and with little reflection, things that are very much NOT what meditation is. How many of you have reflected on prayer, instead of simply repeating it because that's what the pastor is saying/because that's what the next line is on the book? Prayer, unfortunately, is not always, or does not always include reflection, much less meditation.
Two people on the first page mentioned things that boil down to 'depends on the definition', and that much is also true. In my opinion, if one follows the form meditation that the Dalai Lama speaks, the statement in the OP would tend to be true. The next question then becomes "What exactly is meditation/what is meant by OP when they say, 'meditation'?" - the OP fails to elaborate on this (and judging from how they equate two absolutely different types of meditation, I am certain they themselves do not know the intricacies of it), and I don't want to give a crash course on it, so I will not elaborate on the definitions here, rather the overall idea of what meditation, in general, is. That being said, several sects of Buddhism encourage skills/tendencies that can easily be adopted into secular societies/beliefs (or lack thereof), done entirely without needless ceremony or worship. They frown upon those who try to 'spread' Buddhism like it's a product. Among these skills are meditation.
The results of meditation hinges heavily on the individual. You must, on some level, want or at least not be opposed to a result that would disincline you from violence, or at least accept that whatever the results may be, it may. It is absolutely pointless to go into something that has its own specific goal, when internally, you disagree with it. Meditation is heavily internal and subjective, and when you cannot reconcile which result it is you want within yourself, you can meditate for 50 years with no result. This is true not just for meditation, but anything else in life. If violence is what you want, absolutely, at the core, no amount of beating it into yourself with any method (literally and figuratively) would change your inner thoughts and wants.
In my opinion at least, meditation isn't a result, it is a vehicle. It is a knife, so to speak, and the method and end result is up to those who wield it. Meditation (in general, not any specific one) does not make you peaceful/holy/etc necessarily, but it can help you get there, and it is not the only thing that can. Personally, I would not recommend it for absolutely anyone, either. If you want something, you must pick whatever best/efficient method it is for yourself, and that may or may not be meditation.
Proper meditation, (Buddhist or not, but this is also what Buddhism supports), encourages practices and disciplines of mindfulness and honesty towards the self (among other things)- things that can help individuals to sift through their more negative tendencies and equip them to confront and change them during their lucid, non-meditative states. It is not a stretch to imagine that those skills, methods, especially with regular reinforcement, could help an individual in 'retraining' themselves to do, or see things in different ways, and develop the discipline, fortitude, and clarity of mind to go for it.
In my POV and experience, and as someone who had been born and raised into the Buddhist religion, it is ironically Western society that has sold the 'meditate to transform!' shtick that is unfortunately severely reductionist, simplistic, and misleading, no more than a verbal clickbait for people to flock to them. This is absolutely frowned upon in Buddhist practice and I disdain even other Buddhists who fall for/do this.
All in all; my take is to be educated on what it is you're putting in your mind, just as to be physically healthy, it is important to be educated on what you are putting into your own body. Understand what it is and do not be rushed by peer pressure, or anything else. These are the building block foundations to becoming the kind of person you want to be, meditation or not, violent or not.