While certain disclosures are required by law, a disclosure as to every single possible commercial property tax that you may need to pay on a property is not necessarily required. Property tax, school tax and other requirements change relatively regularly, and it is possible that the landlord wasn't even specifically aware of the tax or that it was omitted inadvertently. In any case, it is up to you to do your due diligence before you sign a lease or buy a property, so it is your obligation to just pay the commercial property tax as required by your lease.
Understanding Real Estate Transactions
While various laws govern real estate actions and leases (such as laws that protect tenants from unfair eviction and laws that mandate disclosure of known defects), for the most part, the law allows the parties to set the terms of their agreement themselves. This means if your landlord told you that you were responsible for paying all taxes and you agreed to do so and signed the lease with that clause in there, then you will be held legally responsible for doing so, i.e. - paying all taxes.
Unless some other clause in your lease mandated that each and every tax must be disclosed, there is no requirement that your landlord tell you about exactly what "all taxes" means. When you saw that clause, it was your responsibility to find out what the taxes were and if you didn't do this, then you are going to be the one responsible for dealing with the consequences of not doing your research.
Getting Help
Before you sign any lease, you should have it reviewed by an attorney. This can help you avoid problems like unexpected taxes from arising, since your lawyer will notice any potential problems or red flags in the lease and help you to make sure your rights are fully protected.