Any major implementation of SharePoint / Office 365 should have a training component included in the planning. The type and scale of training is dependent on the size of the project and company. It’s not always easy to sell the benefits of training because there are always significant costs involved and companies are cognizant of costs.
The primary consideration would be how you want your platform managed over the long term. In the beginning, most companies would need a consulting house to set up the intranets for them. But how do you want that to end? If you happy to be completely dependent on the consulting house for up to 5 years, training is not a requirement. However, if you want your staff to manage their own environments and design their own solutions, you will have no choice but to train them.
Some companies decide that they will rather hire their own SharePoint person in a full time roll – these skills are very scarce in this country. Posts have been known to stay open for a year or longer. In the space of a year, you could have upskilled someone internally to fulfill that role and provide that person with a new career opportunity.
Others expect their internal training departments to take over the training of the platform – but train the trainer scenarios seldom work in SharePoint because of the complexity of the platform.
Training users on the solution you built for them is not going to be sufficient for them to take over a platform like SharePoint. They will not have the knowledge they need to understand the bigger picture and how the platform fits together. If you want them to build their own solutions, they have got to have proper power user training with long term support after that available to them and these things take time as SharePoint is a very big platform.
It is critical to budget for training, understand the implications of training vs not training, and what training you need or end up spending a lot more than you bargained for in support and development costs.