There is a limit to what the holder of an easement can do with respect to using and maintaining the easement. Some rights of maintenance and use are spelled out in the easement agreement, and others are implied by the type and purpose of the easement. There is a fair amount of litigation over what constitutes appropriate use of easements. Sometimes the property owner wins, sometimes the easement holder. Common themes are sharing of costs of maintenance when both are users of the easement, whether increased use is an "overburden" of the easement, and whether a locked gate is an unreasonable impairment of the right of use, even if the user is given a key.
In your situation, I would cautiously predict that the utility company would prevail in court, partly because it faces these fire-and-wind damage-prevention issues all the time, and they probably know their rights (and obligations) very well. Keep in mind that the work they're proposing to do (or have done) is expensive, and they probably wouldn't do it unless they had very good reason - such as compliance with CPUC or CDF regulations, or something like that.
Bottom line is that I don't know what a judge would say after hearing all the evidence, and I don't think any attorney can say he or she "knows" what the outcome would be, unless perhaps it is the utility company's own attorney making the prediction based on handling dozens of similar prior cases.
